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 A335264 #8 Jun 25 2020 02:57:14 %S A335264 0,1,1,0,1,0,1,0,17,0,775,0,477481,0,267589,0,3362251073,0, %T A335264 421424697891,0,38751520678991,0,44386209501802003,0, %U A335264 228891128457907983257,0,1636462395711601387189,0,348063222218272291910609213,0,3710225622968600411572814809525 %N A335264 a(n) = Numerator(-4*n^2*Zeta(1 - n)^2*(1 - 2^n)) for n >= 1, a(0) = 0. %F A335264 a(n) = numerator(Bernoulli(n)^2*(2^(n+2) - 4)). %e A335264 Rational sequence starts: 0, 1, 1/3, 0, 1/15, 0, 1/7, 0, 17/15, 0, 775/33, 0, 477481/455, ... %p A335264 a := s -> `if`(s = 0, 0, -4*s^2*Zeta(1 - s)^2*(1 - 2^s)): %p A335264 seq(numer(a(s)), s = 0..24); %Y A335264 Cf. A335265 (denominators), A164555/A027642 (Bernoulli numbers). %Y A335264 Cf. A335538, A335539, A327497. %K A335264 nonn,frac %O A335264 0,9 %A A335264 _Peter Luschny_, Jun 13 2020