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 A328986 #10 Nov 07 2019 21:11:59 %S A328986 4,10,16,21,28,33,39,45,51,57,62,68,74,80,86,91,98,103,109,115,120, %T A328986 127,132,138,144,150,156,161,168,173,179,185,190,197,202,208,214,220, %U A328986 226,231,237,243,249,255,260,267,272,278,284,290,296,301,307,313,319 %N A328986 The sequence C(n) defined in the comments (A and B smallest missing numbers, offset 1). %C A328986 Define a triple of sequences A,B,C by A[1]=1, B[1]=2, C[1]=4; for n>=2, A[n] = smallest missing number from the terms of A,B,C defined so far; B[n] = = smallest missing number from the terms of A,B,C defined so far; C[n] = n+A[n]+B[n]. %C A328986 Then A = A286660, B = A080652, C = the present sequence. %C A328986 Inspired by the triples [A003144, A003145, A004146] and [A298468, A298469, A047218]. %e A328986 The initial terms are: %e A328986 n: 1, 2, 3, 4, 5, 6, 7, 8. 9. 10. 11, 12, ... %e A328986 A: 1, 3, 6, 8, 11, 13, 15, 18, 20, 23, 25, 27, ... %e A328986 B: 2, 5, 7, 9, 12, 14, 17, 19, 22, 24, 26, 29, ... %e A328986 C: 4, 10, 16, 21, 28, 33, 39, 45, 51, 57, 62, 68, ... %Y A328986 Cf. A286660, A080652; A003144, A003145, A003146; A298468, A298469, A047218. %K A328986 nonn %O A328986 1,1 %A A328986 _N. J. A. Sloane_, Nov 07 2019