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 A127250 #7 Aug 04 2023 04:35:29 %S A127250 1,3,5,1,3,1,1,3,5,1,1,3,1,3,5,1,3,1,1,3,1,3,5,1,1,3,5,1,3,1,1,3,5,1, %T A127250 1,3,1,3,5,1,1,3,5,1,3,1,1,3,1,3,5,1,3,1,1,3,5,1,1,3,1,3,5,1,3,1,1,3, %U A127250 1,3,5,1,1,3,5,1,3,1,1,3,1,3,5,1,3,1,1 %N A127250 Sequence consisting of 1,3 or 5 with 3's occurring at the odious indices given by A091855 and 5's occurring at twice these odious indices. %t A127250 a[n_] := If[OddQ[DigitCount[n, 2, 1]], If[EvenQ[IntegerExponent[n, 2]], 3, 5], 1]; Array[a, 100, 0] (* _Amiram Eldar_, Aug 04 2023 *) %Y A127250 Row sums of triangle A127249. %Y A127250 Cf. A000069, A091855. %K A127250 nonn,base %O A127250 0,2 %A A127250 _Paul Barry_, Jan 10 2007 %E A127250 More terms from _Amiram Eldar_, Aug 04 2023