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 A267487 Primes p such that A001221(p+1)^(p-1) == 1 (mod p^2). 1
 2, 3, 7, 31, 127, 1093, 3511, 8191, 131071, 524287 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS No further terms up to 10^9. Are all terms of A000668 and A001220 in the sequence? Does the sequence contain any terms not in A000668 or A001220 other than 2? LINKS MAPLE isA267487 := proc(p)     if isprime(p) then         A001221(p+1) ;         simplify(modp(% &^ (p-1), p^2) =1 );     else         false;     end if; end proc: p := 2; for i from 1 do     if isA267487(p) then         printf("%d\n", p) ;     end if;     p := nextprime(p) ; end do: # R. J. Mathar, Jan 23 2016 MATHEMATICA Select[Prime[Range[3200]], Mod[PrimeNu[# + 1], #^2]^(# - 1) == 1 &] (* G. C. Greubel, Apr 25 2017 *) PROG (PARI) forprime(p=1, 1e9, if(Mod(omega(p+1), p^2)^(p-1)==1, print1(p, ", "))) CROSSREFS Cf. A000668, A001220, A260377. Sequence in context: A228171 A089359 A239892 * A343733 A081947 A046972 Adjacent sequences:  A267484 A267485 A267486 * A267488 A267489 A267490 KEYWORD nonn,more AUTHOR Felix FrÃ¶hlich, Jan 15 2016 STATUS approved

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Last modified September 27 08:39 EDT 2021. Contains 347689 sequences. (Running on oeis4.)