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 A026603 #13 Apr 23 2021 05:55:37 %S A026603 3,5,7,11,13,18,19,24,26,29,31,36,37,42,44,48,50,52,55,60,62,66,68,70, %T A026603 74,76,81,83,85,90,91,96,98,102,104,106,109,114,116,120,122,124,128, %U A026603 130,135,138,140,142,146,148,153,154,159,161 %N A026603 Numbers k such that A026600(k) = 3. %C A026603 It appears that a(n) gives the position of its own n-th 1 modulo 3 term, the n-th 2 modulo 3 term in A026601, and the n-th multiple of 3 in A026602. A026601 and A026602 appear to have the same sort of indexical properties. - _Matthew Vandermast_, Oct 06 2010 %Y A026603 Cf. A026600, A026601, A026602. %K A026603 nonn %O A026603 1,1 %A A026603 _Clark Kimberling_