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 A277189 #21 Jan 01 2024 19:48:27 %S A277189 1,5,13,21,45,93,109,85,173,477,957,733,749,1501,877,341,685,3549, %T A277189 12221,7133,14269,49021,28605,5853,5869,30685,61373,23517,12013,24029, %U A277189 7021,1365,2733,28125,192445,97245,384957,2031485,1032125,113629,227261,4128637,16252669,3112829,1564605,6225789,913341,46813,46829,915421 %N A277189 Odd bisection of A277020: a(n) = A277020(2n+1). %H A277189 Antti Karttunen, <a href="/A277189/b277189.txt">Table of n, a(n) for n = 0..8191</a> %F A277189 a(n) = A277020(2*n + 1). %F A277189 a(n) = A156552(A277324(n)). %F A277189 Other identities. For all n >= 0: %F A277189 a(n) = 1 mod 4. %o A277189 (Scheme) (define (A277189 n) (A277020 (+ n n 1))) %Y A277189 Cf. A156552, A277020, A277324. %Y A277189 Terms form a proper subset of A247648. %K A277189 nonn,look %O A277189 0,2 %A A277189 _Antti Karttunen_, Oct 08 2016 %E A277189 Offset changed from 1 to 0 by _Antti Karttunen_, Oct 11 2016