cp's OEIS Frontend

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.

A340494 Index where n first appears in A340488.

Original entry on oeis.org

1, 3, 6, 8, 16, 18, 21, 23, 56, 58, 61, 63, 71, 73, 76, 78, 216, 218, 221, 223, 231, 233, 236, 238, 271, 273, 276, 278, 286, 288, 291, 293, 856, 858, 861, 863, 871, 873, 876, 878, 911, 913, 916, 918, 926, 928, 931, 933, 1071, 1073, 1076, 1078, 1086, 1088, 1091
Offset: 0

Views

Author

N. J. A. Sloane, Jan 10 2021

Keywords

Comments

The first differences appear to be some kind of ruler sequence separated by 2's.
indeed, the first differences look like n -> f(A001511(n)) with f = (2, 3, 8, 33, 138, 563, 2268, 9093, 36398, 145623, 582528, 2330153, 9320658, etc.). See A340495. - Rémy Sigrist, Jan 10 2021

Crossrefs

Programs

  • PARI
    See Links section.

Formula

The generating function appears to be
1/(1-x ) + 2*x/(1-x)^2 + (1/(1-x))*Sum_{t>=1} x^(2^t)*(g(t+1)-g(t))/(1-x^(2^t)),
where g = {g(t): t >= 1} = 2,3,8,33,138,... has g.f. x*(2*x-1)*(2*x^2+5*x-2)/((1-x)^2*(1-4*x)). - Rémy Sigrist and N. J. A. Sloane, Jan 10 2021

Extensions

More terms from Rémy Sigrist, Jan 10 2021