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.

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A275934 Shifts 4 places left under binomial transform.

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 1, 4, 10, 20, 36, 68, 166, 540, 1961, 7012, 23878, 78004, 250311, 815196, 2787806, 10232556, 40266382, 166608080, 708407020, 3046352440, 13161936881, 57188405288, 251328286460, 1125890398160, 5177570523461, 24539362719532, 119861818560962, 601299401594540, 3082695751138656, 16075855888601716, 85005009812011810, 455172001509369028, 2468935975119176601, 13584735197391443020
Offset: 0

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Author

Olivier Gérard, Aug 12 2016

Keywords

Crossrefs

Formula

Sum_{i=0..n} binomial(n,i)*a(i) = a(n+4).
G.f. A(x) satisfies: A(x) = x^3 + x^4 * A(x/(1 - x)) / (1 - x). - Ilya Gutkovskiy, Jul 01 2021

A351345 G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 + x^4 + x^5 + x^6 * A(x/(1 - 2*x)) / (1 - 2*x).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 3, 9, 27, 81, 243, 729, 2189, 6601, 20141, 63009, 205989, 718905, 2720543, 11183601, 49321367, 228895201, 1097860903, 5371546897, 26598018425, 132755261681, 667027581401, 3376011676481, 17249045903945, 89270689572497, 470069622480667
Offset: 0

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Author

Ilya Gutkovskiy, Feb 08 2022

Keywords

Comments

Shifts 6 places left under 2nd-order binomial transform.

Crossrefs

Programs

  • Mathematica
    nmax = 31; A[] = 0; Do[A[x] = 1 + x + x^2 + x^3 + x^4 + x^5 + x^6 A[x/(1 - 2 x)]/(1 - 2 x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[n_] := a[n] = If[n < 6, 1, Sum[Binomial[n - 6, k] 2^k a[n - k - 6], {k, 0, n - 6}]]; Table[a[n], {n, 0, 31}]

Formula

a(0) = ... = a(5) = 1; a(n) = Sum_{k=0..n-6} binomial(n-6,k) * 2^k * a(n-k-6).
Showing 1-2 of 2 results.