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.

Showing 1-2 of 2 results.

A291653 a(n) = [x^n] (1/(1 - x/(1 - x^2/(1 - x^3/(1 - x^4/(1 - x^5/(1 - ...)))))))^n, a continued fraction.

Original entry on oeis.org

1, 1, 3, 13, 55, 236, 1035, 4593, 20551, 92578, 419338, 1907951, 8713555, 39921038, 183396671, 844515563, 3896933367, 18014916576, 83415684654, 386807933378, 1796024496430, 8349190182990, 38854827380075, 180997895984903, 843906670596499, 3938005827167461, 18390418912425940
Offset: 0

Views

Author

Ilya Gutkovskiy, Aug 28 2017

Keywords

Crossrefs

Main diagonal of A291652.

Programs

  • Mathematica
    Table[SeriesCoefficient[1/(1 + ContinuedFractionK[-x^i, 1, {i, 1, n}])^n, {x, 0, n}], {n, 0, 26}]

Formula

a(n) = A291652(n,n).
a(n) ~ c * d^n / sqrt(n), where d = 4.760595370947474723688065553003203505424287110594102605580439495640678... and c = 0.22756527349964754363249384886359862025065238... - Vaclav Kotesovec, Apr 08 2018

A291701 Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of k-th power of continued fraction 1 - x/(1 - x^2/(1 - x^3/(1 - x^4/(1 - x^5/(1 - ...))))).

Original entry on oeis.org

1, 1, 0, 1, -1, 0, 1, -2, 0, 0, 1, -3, 1, -1, 0, 1, -4, 3, -2, 0, 0, 1, -5, 6, -4, 2, -1, 0, 1, -6, 10, -8, 6, -2, -1, 0, 1, -7, 15, -15, 13, -6, 1, -1, 0, 1, -8, 21, -26, 25, -16, 6, 0, -2, 0, 1, -9, 28, -42, 45, -36, 18, -3, 0, -2, 0, 1, -10, 36, -64, 77, -72
Offset: 0

Views

Author

Seiichi Manyama, Aug 30 2017

Keywords

Examples

			Square array begins:
   1,  1,  1,  1,  1, ...
   0, -1, -2, -3, -4, ...
   0,  0,  1,  3,  6, ...
   0, -1, -2, -4, -8, ...
   0,  0,  2,  6, 13, ...
		

Crossrefs

Columns k=0..1 give A000007, A291148.
Rows n=0..1 give A000012, A001489.
Main diagonal gives A291702.
Cf. A291652.

Formula

G.f. of column k: (1 - x/(1 - x^2/(1 - x^3/(1 - x^4/(1 - x^5/(1 - ...))))))^k, a continued fraction.
Showing 1-2 of 2 results.