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 A087189 #20 Apr 22 2025 03:39:29
%S A087189 1,83,16907,279021,89444018,1695011087,658067703933,5768410509553937,
%T A087189 122108313460051500,1226978854222034501448,593538703869555995238872,
%U A087189 13175226571428140572866093,6594852118968926152838341468,76339779380132942579800334346403
%N A087189 (P(p)-1)/2/p^2 where p runs through the odd primes different from 5 and P(k) is the k-th central pentanomial coefficient (A005191).
%H A087189 Amiram Eldar, <a href="/A087189/b087189.txt">Table of n, a(n) for n = 1..226</a> (terms 1..100 from M. F. Hasler)
%t A087189 f[n_] := Max[CoefficientList[Expand[Sum[x^k, {k, 0, 4}]^n], x]]; Table[(f[p] - 1)/(2*p^2), {p, Prime[Delete[Range[2, 15], 2]]}] (* _Amiram Eldar_, Apr 22 2025 *)
%o A087189 (PARI) A087189(n) = local(p=prime(n+2-(n==1))); (A005191(p)-1)/2/p^2 \\ _M. F. Hasler_, Jul 23 2007
%Y A087189 Cf. A005191.
%K A087189 nonn
%O A087189 1,2
%A A087189 _Benoit Cloitre_, Oct 19 2003
%E A087189 Corrected and extended by _M. F. Hasler_, Jul 23 2007