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 A181426 #17 Jul 03 2025 16:23:53
%S A181426 1,17,49,59,979,91,167,731,5111,517,1817,6071,109,18241,22289,2771,
%T A181426 131,28823,67,51619,11911,34891,15557,257,1949,22313,2267,14123,
%U A181426 153931,5273999,1,3167,45091,3569,268309,126947,4217,127,369641,201679,85739
%N A181426 Numerator of Sum_{k=1..n} k^4 / Product_{k=1..n} k^4.
%C A181426 a(n) = 1 for n = {1, 31, 59, 94, 104, 122, 133, 181, 206, 223, ...} = A166604.
%H A181426 Harvey P. Dale, <a href="/A181426/b181426.txt">Table of n, a(n) for n = 1..1000</a>
%e A181426 The first few fractions are 1, 17/16, 49/648, 59/55296, 979/207360000, 91/10749542400, 167/23044331520000, ... = A181426/A334734.
%t A181426 Table[Numerator[Sum[ k^4, {k, 1, n}] / Product[k^4, {k, 1, n}]], {n, 1, 100}]
%t A181426 With[{c=Range[50]^4},Numerator[Accumulate[c]/FoldList[Times,c]]] (* _Harvey P. Dale_, Jul 03 2025 *)
%o A181426 (PARI) a(n) = numerator(sum(k=1, n, k^4)/prod(k=1, n, k^4)); \\ _Michel Marcus_, May 09 2020
%Y A181426 Cf. A090585 = Numerator of Sum/Product of first n numbers.
%Y A181426 Cf. A125294 = Numerator of Sum/Product of squares of first n numbers.
%Y A181426 Cf. A166604, A334734 (denominators).
%K A181426 nonn,frac
%O A181426 1,2
%A A181426 _Alexander Adamchuk_, Oct 18 2010