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.

A141397 a(n) = 3*a(n-1) + A001651(n+1).

Original entry on oeis.org

1, 5, 19, 62, 193, 587, 1771, 5324, 15985, 47969, 143923, 431786, 1295377, 3886151, 11658475, 34975448, 104926369, 314779133, 944337427, 2833012310, 8499036961, 25497110915, 76491332779, 229473998372, 688421995153, 2065265985497, 6195797956531, 18587393869634
Offset: 0

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Author

Gary W. Adamson, Jun 29 2008

Keywords

Comments

Row sums of triangle A141396.

Examples

			a(2) = 19 = 3*a(1) + A001651(3) = 3*5 + 4 where A001651(3) = 4.
a(2) = 19 = sum of row 2 terms of triangle A141396: (4 + 6 + 9).
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{4,-2,-4,3},{1,5,19,62},50] (* Harvey P. Dale, Jul 07 2024 *)
  • PARI
    Vec((-1-x-x^2) / ((1+x)*(3*x-1)*(x-1)^2) + O(x^40)) \\ Michel Marcus, Jan 21 2015

Formula

G.f.: ( -1-x-x^2 ) / ( (1+x)*(3*x-1)*(x-1)^2 ). a(n) = (-1)^n/16 -3*n/4 -3/2 +13*3^(n+1)/16. - R. J. Mathar, Feb 16 2011