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 A363403 #5 Jun 08 2023 08:50:13 %S A363403 0,1,2,28,8,496,96,8128,2176,130816,15872,2096128,6144,33550336, %T A363403 44736512,536854528,8421376,8589869056,86114304,137438691328, %U A363403 3331850240,2199022206976,127479578624,35184367894528,103104380928,562949936644096,750599926710272,9007199187632128 %N A363403 a(n) = (4^n - 2^n) / Clausen(n, 1). %F A363403 a(n) = A020522(n) / A160014(n, 1). %p A363403 # Using function 'Clausen' from A160014. %p A363403 a := n -> (4^n - 2^n) / Clausen(n, 1): %p A363403 seq(a(n), n = 0..25); %Y A363403 Cf. A160014, A363402, A363395. %K A363403 nonn %O A363403 0,3 %A A363403 _Peter Luschny_, Jun 08 2023