OEIS gripes

David W. Wilson wilson at aprisma.com
Fri Jul 6 20:02:26 CEST 2001


I was looking at some of your recent sequences.  Many are incorrect,
duplicates, or unjustifiably short sequences (easily filled out).

As much as I love the OEIS, it looks as if it is becoming a dumping
ground for some very poor-quality stuff in terms of correctness and
relevancy.  The OEIS would certainly benefit from a review process.

To underscore my point, here is an analysis of some sequences from
the recent sequences list:

------------------------------------------------------------------------
A062931 = incorrect and short version of A025527.

A062932 correct but short and easily extended.  Extended sequence:
1 2 3 4 5 6 16 17 27 28 38 39 49 50 51 60 61 70 71 80 81 90 91 100 102
110 112 120 122 130 132 140 142 150 153 160 163 170 173 180 183 190 193
200 204 210 214 220 224 230 234 240 244 250 255 260 265 270 275 280 285

A062933 = incorrect and short version of A028337.

A062934 = incorrect and short version of A057135.

A062935 correct, probably finite and full.

A062936 incorrect and short.  Corrected and extended sequence:
1 2 3 11 12 21 22 101 102 111 112 121 122 201 202 211 212 221 1001 1002
1011 1012 1021 1022 1101 1102 1111 1112 1121 1201 1202 1211 2001 2002
2011 2012 2021 2101 2102 2111 2201 10001 10002 10011 10012 10021 10022
Comment: Integers not ending in 0 with sum of squares of digits < 10.

A062937 is incorrect and short.  Corrected and extended sequence:
1 2 3 4 5 6 7 8 9 11 22 33 44 55 66 77 88 99 101 121 131 151 181 191
202 242 262 303 313 353 363 373 383 393 404 484 505 606 626 707 727 757
787 797 808 909 919 929 939 1111 1331 1441 1661 1991 2222 2662 2882

A062938 is short and  missing a(0) = 1.  Corrected and extended sequence:
1 25 121 361 841 1681 3025 5041 7921 11881 17161 24025 32761 43681
57121 73441 93025 116281 143641 175561 212521 255025 303601 358801
421201 491401 570025 657721 755161 863041 982081 1113025 1256641

A060648 has a difficult description as a multiplicative function.
I am guessing that it is multiplicative with
    f(p^e) = 1 if e = 0, p*f(p,e-1)+2 if e >= 1.
If so, it easily extends to
1 4 5 10 7 20 9 22 17 28 13 50 15 36 35 46 19 68 21 70 45 52 25 110 37
60 53 90 31 140 33 94 65 76 63 170 39 84 75 154 43 180 45 130 119 100
49 230 65 148 95 150 55 212 91 198 105 124 61 350 63 132 153 190 105

A062004 is correct, questionably relevant.

A062007 is correct, questionably relevant.

A062008 is interesting.

A062039 is really pi(n!).  I added two elements.  I assume someone
with a boss pi(n) algorithm could easily add a few more.
0 0 1 3 9 30 128 675 4231 30969 258689

A062274 I was able to extend a little:
0 0 1 7 45 291 2030 15695 135045 1287243 13495669

A062282 has a formula.  We ought to be able to extend it easily.

A062304 was easy to extend a few elements:
0 0 1 1 2 2 5 3 8 11 22 25 53 76 151 244 435 749 1314 2367 4239 7471
13705

A062307 should not include 1.  When it is removed, it become A000469.





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