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 A078277 #18 Jun 26 2025 07:41:56
%S A078277 1,121,13941,1577761,176141581,1028725268301,10304701810650121,
%T A078277 103228853737447031941,1034106901028283083413761,
%U A078277 10359252646828302828719795581,111956181015555937395556174359301,1121388355628288465046488283629741121
%N A078277 a(n) = A078274(n)/11.
%o A078277 (PARI) a(n) = {my(d, v=w=[1]); for(i=2, n, v=concat(v, d=digits(2*i-1)); w=concat(d, w)); fromdigits(vector(2*#v, i, if(i%2, v[1+i\2], w[i/2])))/11; } \\ Jinyuan Wang, May 17 2020 [Updated by _Sean A. Irvine_, Jun 26 2025]
%Y A078277 Cf. A078274, A078275, A078276.
%K A078277 nonn,base
%O A078277 1,2
%A A078277 _Amarnath Murthy_, Nov 25 2002
%E A078277 More terms from _Sean A. Irvine_, Aug 15 2011
%E A078277 Corrected by _Sean A. Irvine_, May 30 2013
%E A078277 Correction reverted by _Sean A. Irvine_, Jun 26 2025