Silly sequences (Was:: EURE)

[zak seidov]

Another silly sequence
is get if we demand that 
"nextprime" may be ALSO "previousprime":
among first 1,000 "normal" primes 
there are only 24 such NP-silly primes:

5,13,17,103,197,227,787,823,911,919,1153,1409,1487,1723,2087,2647,2767,2999,3001,3389,6089,6781,6827,7877

e.g. 5+7+5=15 and 5+3+5=13,
13+17+13=43 and 13+11+13=41, etc.

(* You may of course take only "previousprime",
such P-silly primes are much more numerous (189 among
first 1000:
5, 7, 11, 13, 17, 43, 47, 61, 97, 103, 107, etc
*)

According to Neil,s "new" rule the first (JZ's)
N-silly pimes sequence may be sent to OEIS, my new
one(s) sequency is(are) pending reaction of SF's...

HNY!, Zak

--- Joshua Zucker <joshua.zucker at gmail.com> wrote:

> On 12/16/06, Jonathan Post <jvospost3 at gmail.com>
> wrote:
> > the fact that the number of syllables in a haiku
> is prime.
> 
> OK, then, how about this (silly!) sequence:
> "Haiku primes" are primes p such that p +
> nextprime(p) + p is also prime.
> For example, 5 is the canonical haiku prime because
> 5, 7, and 5 are
> all prime, and so is 5+7+5.
> 
> [Of course, there could be argument about where the
> 7 comes from: is
> it nextprime(p) or is it p+2 or is it some other
> function?  If it's
> p+2 then the sequence is already in OEIS as A023208]
> 
> Haiku primes up to 10000:
> 2 3 5 13 17 19 29 59 79 103 109 113 149 197 223 227
> 229 239 241 269
> 283 337 349 409 419 439 491 569 577 643 659 691 701
> 709 739 743 769
> 773 787 823 839 911 919 983 1051 1153 1213 1277 1373
> 1409 1423 1427
> 1471 1487 1549 1571 1609 1637 1663 1667 1699 1723
> 1801 1823 1873 1879
> 1949 2039 2087 2089 2129 2221 2243 2267 2273 2293
> 2339 2423 2477 2521
> 2539 2549 2647 2683 2719 2741 2753 2767 2789 2843
> 2917 2939 2953 2971
> 2999 3001 3011 3079 3109 3137 3359 3361 3389 3413
> 3469 3547 3571 3739
> 3769 3779 3793 3929 3943 3967 4049 4129 4157 4201
> 4217 4229 4231 4243
> 4273 4363 4517 4583 4621 4637 4639 4663 4861 4909
> 5051 5099 5153 5281
> 5417 5449 5477 5531 5653 5659 5669 5779 5791 5881
> 5903 5987 6043 6089
> 6197 6203 6221 6299 6301 6359 6473 6521 6569 6637
> 6659 6679 6781 6793
> 6827 6833 6949 6959 7039 7043 7127 7283 7507 7547
> 7559 7589 7639 7669
> 7673 7691 7723 7789 7873 7877 8009 8219 8243 8387
> 8419 8539 8581 8597
> 8609 8623 8753 8819 8837 8941 9173 9241 9257 9311
> 9319 9323 9349 9403
> 9463 9677 9739 9767 9857 9929 9931
> 
> Enjoy,
> --Joshua Zucker
> 


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