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 A087489 #19 Jul 18 2022 10:00:54
%S A087489 7,11,13,19,23,37,41,43,47,61,67,71,73,79,83,89,97,103,107,109,113,
%T A087489 127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,
%U A087489 223,227,229,233,239,241,251,257,263,269,271,281,283,293,307,311,313,317
%N A087489 Primes p such that 3^p - 2^p is composite.
%H A087489 Harvey P. Dale, <a href="/A087489/b087489.txt">Table of n, a(n) for n = 1..1000</a>
%t A087489 Select[Prime[Range[100]],CompositeQ[3^#-2^#]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Feb 18 2018 *)
%o A087489 (PARI) apmb(a,b,n) = { forprime(x=2,n, y=a^x-b^x; if(!ispseudoprime(y), print1(x","); ) ) }
%Y A087489 Cf. A001047.
%Y A087489 Primes p such that k^p - (k-1)^p is composite: this sequence (k=3), A087490 (k=4), A087685 (k=5), A087749 (k=6), A087759 (k=7), A087763 (k=8), A087894 (k=9), A087895 (k=10).
%K A087489 nonn
%O A087489 1,1
%A A087489 _Cino Hilliard_, Oct 26 2003
%E A087489 Offset corrected by _Mohammed Yaseen_, Jul 17 2022