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.

A092119 EULER transform of A001511.

Original entry on oeis.org

1, 1, 3, 4, 10, 13, 26, 35, 66, 88, 150, 202, 331, 442, 688, 919, 1394, 1848, 2716, 3590, 5174, 6796, 9589, 12542, 17440, 22680, 31055, 40208, 54420, 70096, 93772, 120256, 159380, 203436, 267142, 339573, 442478, 560050, 724302, 913198, 1173375, 1473622
Offset: 0

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Author

Vladeta Jovovic, Mar 29 2004

Keywords

Comments

From Gary W. Adamson, Feb 11 2010: (Start)
Given A000041, P(x) = A(x)/A(x^2) with P(x) = (1 + x + 2x^2 + 3x^3 + 5x^4 + 7x^5 + ...),
A(x) = (1 + x + 3x^2 + 4x^3 + 10x^4 + 13x^5 + ...),
A(x^2) = (1 + x^2 + 3x^4 + 4x^6 + 10x^8 + ...), where A092119 = (1, 1, 3, 4, 10, ...) = Euler transform of the ruler sequence, A001511. (End)
Let M = triangle A173238 as an infinite lower triangular matrix. Then A092119 = lim_{n->infinity} M^n. Let P(x) = polcoeff A000041 = (1 + x + 2x^2 + 3x^3 + ...), and A(x) = polcoeff A092119. Then P(x) = A(x) / A(x^2), an example of a conjectured infinite set of operations (cf. A173238). - Gary W. Adamson, Feb 13 2010

Crossrefs

Cf. A000041. - Gary W. Adamson, Feb 11 2010
Cf. A173241.

Programs

  • Maple
    # Uses EulerTransform from A358369.
    t := EulerTransform(n -> padic[ordp](2*n, 2)):
    seq(t(n), n = 0..41); # Peter Luschny, Nov 18 2022
  • Mathematica
    m = 42;
    1/Product[QPochhammer[x^(2^k)], {k, 0, Log[2, m]//Ceiling}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Jan 14 2020, after Joerg Arndt *)
  • PARI
    N=66; x='x+O('x^N); /* that many terms */
    gf=1/prod(e=0,ceil(log(N)/log(2)),eta(x^(2^e)));
    Vec(gf) /* show terms */ /* Joerg Arndt, Jun 21 2011 */

Formula

G.f.: 1/Product_{k>=0} P(x^(2^k)) where P(x) = Product_{k>=1} (1 - x^k). - Joerg Arndt, Jun 21 2011