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.

A356900 a(n) = P(n, 1/2) where P(n, x) = x^(-n)*Sum_{k=0..n} A241171(n, k)*x^k.

Original entry on oeis.org

1, 1, 8, 154, 5552, 321616, 27325088, 3200979664, 494474723072, 97390246272256, 23820397371219968, 7083386168647642624, 2516691244849530785792, 1052914814802404260765696, 512347915163742179541659648, 286902390859642414913802102784, 183187476890368376930869730803712
Offset: 0

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Author

Peter Luschny, Sep 03 2022

Keywords

Comments

Other special values of this Euler type polynomials are: P(n, -1) = A000364(n); P(n, -1/2) = A002105(n); P(n, 1) = A094088(n), where we always make the assumption that the offset of the sequences is 0. A partition refinement of Joffe's triangle A241171 is A327022.

Crossrefs

Programs

  • Maple
    a := n -> 2^n*add(A241171(n, k)*(1/2)^k, k = 0..n):
    seq(a(n), n = 0..16);
  • SageMath
    # Using function PtransMatrix from A269941.
    def E(n, v):
        eulr = lambda n: 1 / ((2 * n - 1) * (2 * n))
        norm = lambda n, k: (1 / v)^n * factorial(2 * n)
        P = PtransMatrix(n, eulr, norm)
        return [(-1)^j * sum([v^k * P[j][k] for k in range(j + 1)]) for j in range(n)]
    A356900List = lambda n: E(n, -1/2); print(A356900List(17))
    # A002105List = lambda n: E(n, 1/2) returns the reduced tangent numbers A002105.