This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A087759 #14 Jul 19 2022 01:20:30 %S A087759 5,11,13,17,19,23,31,37,43,47,53,59,61,71,73,79,83,89,97,101,103,107, %T A087759 109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197, %U A087759 199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293 %N A087759 Primes p such that 7^p - 6^p is composite. %t A087759 Select[Prime[Range[70]],CompositeQ[7^#-6^#]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 12 2019 *) %o A087759 (PARI) apmb(a,b,n) = { forprime(x=2,n, y=a^x-b^x; if(!ispseudoprime(y), print1(x","); ) ) } %Y A087759 Cf. A016169. %Y A087759 Primes p such that k^p - (k-1)^p is composite: A087489 (k=3), A087490 (k=4), A087685 (k=5), A087749 (k=6), this sequence (k=7), A087763 (k=8), A087894 (k=9), A087895 (k=10). %K A087759 nonn %O A087759 1,1 %A A087759 _Cino Hilliard_, Oct 26 2003 %E A087759 Offset corrected by _Mohammed Yaseen_, Jul 18 2022