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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A238374 Row sums of triangle in A204026.

Original entry on oeis.org

1, 2, 4, 6, 9, 12, 17, 22, 30, 38, 51, 64, 85, 106, 140, 174, 229, 284, 373, 462, 606, 750, 983, 1216, 1593, 1970, 2580, 3190, 4177, 5164, 6761, 8358, 10942, 13526, 17707, 21888, 28653, 35418, 46364, 57310, 75021, 92732, 121389, 150046, 196414, 242782
Offset: 0

Views

Author

Philippe Deléham, Feb 25 2014

Keywords

Examples

			Triangle in A204026 begins:
1;.........................sum = 1
1, 1;......................sum = 2
1, 2, 1;...................sum = 4
1, 2, 2, 1;................sum = 6
1, 2, 3, 2, 1;.............sum = 9
1, 2, 3, 3, 2, 1;..........sum = 12
1, 2, 3, 5, 3, 2, 1;.......sum = 17
1, 2, 3, 5, 5, 3, 2, 1;....sum = 22
1, 2, 3, 5, 8, 5, 3, 2, 1;.sum = 30
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{1,1,-1,1,-1},{1,2,4,6,9},50] (* Harvey P. Dale, Feb 24 2018 *)

Formula

G.f.: (1+x)*(1+x^2)/((1-x^2-x^4)*(1-x)).
a(n) = a(n-1) + a(n-2) - a(n-3) + a(n-4) - a(n-5), a(0) = 1, a(1) = 2, a(2) = 4, a(3) = 6, a(4) = 9.
a(2*n) = A157728(n+5) = A000045(n+5) - 4.
a(2*n+1) = 2*A001911(n+1) = 2*A000045(n+4) - 4.
Previous Showing 11-11 of 11 results.