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.

A136396 a(n) = 1 + n*(n+1)*(n^2-n+12)/12.

Original entry on oeis.org

1, 3, 8, 19, 41, 81, 148, 253, 409, 631, 936, 1343, 1873, 2549, 3396, 4441, 5713, 7243, 9064, 11211, 13721, 16633, 19988, 23829, 28201, 33151, 38728, 44983, 51969, 59741, 68356, 77873, 88353, 99859, 112456, 126211, 141193, 157473, 175124, 194221, 214841, 237063, 260968, 286639
Offset: 0

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Author

Gary W. Adamson, Dec 29 2007

Keywords

Comments

Equals antidiagonal sums of the array A179000.

Examples

			a(3) = 19 = (1, 3, 3, 1) dot (1, 2, 3, 3) = (1 + 6 + 9 + 3).
a(3) = 19 = (1, 6, 6, 1) dot (1, 2, 1, 0) = (1 + 12 + 6 + 0), where (1, 6, 6, 1) = row 4 of the Narayana triangle (A001263).
		

Crossrefs

Programs

  • Maple
    A136396 := proc(n) 1+n*(n+1)*(n^2-n+12)/12 ; end proc:
  • Mathematica
    Table[1+n(n+1)(n^2-n+12)/12,{n,0,50}] (* or *) LinearRecurrence[{5,-10,10,-5,1},{1,3,8,19,41},50] (* Harvey P. Dale, Feb 06 2019 *)

Formula

A007318 * [1,2,3,2,0,0,0,...]: Binomial transform of [1, 2, 3, 3, 2, 0, 0, 0, ...].
Narayana transform of [1,2,1,0,0,0,...]: (A001263) * [1, 2, 1, 0, 0, 0, ...].
G.f.: ( -1+2*x-3*x^2+x^3-x^4 ) / (x-1)^5. - R. J. Mathar, Jan 05 2011