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 A016864 #21 Jul 08 2025 05:57:13
%S A016864 1,1296,14641,65536,194481,456976,923521,1679616,2825761,4477456,
%T A016864 6765201,9834496,13845841,18974736,25411681,33362176,43046721,
%U A016864 54700816,68574961,84934656,104060401,126247696
%N A016864 a(n) = (5*n + 1)^4.
%H A016864 Amiram Eldar, <a href="/A016864/b016864.txt">Table of n, a(n) for n = 0..10000</a>
%H A016864 Eric Weisstein's MathWorld, <a href="https://mathworld.wolfram.com/PolygammaFunction.html">Polygamma Function</a>.
%H A016864 Wikipedia, <a href="http://en.wikipedia.org/wiki/Polygamma_function">Polygamma Function</a>.
%H A016864 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).
%F A016864 Sum_{n>=0} 1/a(n) = polygamma(3, 1/5)/3750. - _Amiram Eldar_, Oct 02 2020
%F A016864 a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). - _Wesley Ivan Hurt_, Oct 02 2020
%F A016864 G.f.: -(1+1291*x+8171*x^2+5281*x^3+256*x^4)/(-1+x)^5. - _Wesley Ivan Hurt_, Oct 02 2020
%e A016864 a(0) = (5*0 + 1)^4 = 1.
%t A016864 Table[(5*n + 1)^4, {n, 0, 25}] (* _Amiram Eldar_, Oct 02 2020*)
%t A016864 LinearRecurrence[{5,-10,10,-5,1},{1,1296,14641,65536,194481},30] (* _Harvey P. Dale_, Jul 22 2021 *)
%Y A016864 Cf. A016861, A016862, A016863.
%K A016864 nonn,easy
%O A016864 0,2
%A A016864 _N. J. A. Sloane_