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.

A347011 Euler transform of j-> ceiling(2^(j-2)).

Original entry on oeis.org

1, 1, 2, 4, 9, 19, 43, 93, 207, 453, 999, 2185, 4796, 10470, 22871, 49815, 108427, 235515, 511074, 1107248, 2396299, 5179169, 11181877, 24113939, 51949572, 111801422, 240381703, 516355235, 1108186951, 2376314763, 5091422730, 10900063776, 23317805916
Offset: 0

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Author

Alois P. Heinz, Aug 10 2021

Keywords

Comments

Differs from A206301 first at n=10.

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
          b(n-i*j, i-1)*binomial(ceil(2^(i-2))+j-1, j), j=0..n/i)))
        end:
    a:= n-> b(n$2):
    seq(a(n), n=0..35);
    # second Maple program:
    a:= proc(n) option remember; `if`(n=0, 1, add(a(n-j)*add(d*
           ceil(2^(d-2)), d=numtheory[divisors](j)), j=1..n)/n)
        end:
    seq(a(n), n=0..35);
  • Mathematica
    CoefficientList[Series[1/(1-x) * Product[1/(1 - x^k)^(2^(k-2)), {k, 2, 40}], {x, 0, 40}], x] (* Vaclav Kotesovec, Aug 11 2021 *)

Formula

G.f.: Product_{j>0} 1/(1-x^j)^ceiling(2^(j-2)).