[seqfan] possible duplicates
Douglas McNeil
mcneil at hku.hk
Sun Aug 15 13:30:29 CEST 2010
Aren't these duplicates?
--
http://oeis.org/classic/?q=id%3AA140433|id%3AA155934
A140433 Primes of the form (n+0)^0+(n+1)^1+(n+2)^2+(n+3)^3+(n+4)^4.
701, 2647, 3381, 7129, 15731, 53551, 110161, 405001, 473201, 549667
A155934 Primes of the form : n^0+(n+1)^1+(n+2)^2+(n+3)^3+(n+4)^4.
701, 2647, 4481, 7129, 15731, 53551, 110161, 405001, 473201, 549667,
1079297, 1541051, 1922077, 6892651, 8654689, 10734697, 13168801,
15995071, 30380849, 33789601, 55322081, 72401057, 85800961, 113622391,
147716801, 238297249
But 3381 isn't prime. (Came across this one when looking for
properties of 2647 for Zak's question.)
--
Two word-based sequences:
http://oeis.org/classic/?q=55893641747
A072959 a(n) = the name of n evaluated in base 27, using blank=0,
hyphen=0, A=1, B=2,... Z=26.
515904, 11318, 15216, 10799546, 129618, 125258, 14118, 10211981,
2839691, 282506, 14729, 78236429, 299309045, 212445531527,
68884716992, 2457249197, 7503281492, 5427065792075, 55893641747,
150135668600, 299310469
A087096 Using the US English name for the nonnegative integers,
assign each letter a numerical value as in A073327 (A=1, B=2, ...,
Z=26) and treat the name as a base-27 integer. Convert to decimal.
515904, 11318, 15216, 10799546, 129618, 125258, 14118, 10211981,
2839691, 282506, 14729, 78236429, 299309045, 212445531527,
68884716992, 2457249197, 7503281492, 5427065792030, 55893641747,
150135668600, 299310469
I think these are supposed to be the same sequence. The second also
seems wrong at 17. I can match A072959's results, and it has a code
posted, so I propose killing A087096 (and changing A072959's offset).
--
http://oeis.org/classic/index.html?q=id%3AA038875|id%3AA003630
A038875 3 is not a square mod p.
2, 5, 7, 17, 19, 29, 31, 41, 43, 53, 67, 79, 89, 101, 103, 113, 127,
137, 139, 149, 151, 163, 173, 197, 199, 211, 223, 233, 257, 269, 271,
281, 283, 293, 307, 317, 331, 353, 367, 379, 389, 401, 439, 449, 461,
463
Isn't 3 a square mod 2? 3=1 mod 2, and 1 is a square. (Maybe a "3 in
set of squares mod p" instead of "3 mod p in set of squares mod p"
bug, which I've made myself repeatedly.) After removing 2, this looks
like
A003630 Inert rational primes in Q(sqrt 3).
5, 7, 17, 19, 29, 31, 41, 43, 53, 67, 79, 89, 101, 103, 113, 127,
137, 139, 149, 151, 163, 173, 197, 199, 211, 223, 233, 257, 269, 271,
281, 283, 293, 307, 317, 331, 353, 367, 379, 389, 401, 439, 449, 461,
463, 487, 499, 509, 521, 523, 547, 557, 569, 571, 593
to me but I may be misunderstanding the definition of inert.
Each of the above sequences differs from its (possible) duplicate
because of an error, which may explain why they weren't noticed at
submission time (and why duplicate searching needs to be
fault-tolerant). Or maybe the errors are mine!
Doug
--
Department of Earth Sciences
University of Hong Kong
More information about the SeqFan
mailing list