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.

A230435 Triangle by rows, A001047 convolved with A000079.

Original entry on oeis.org

1, 2, 5, 4, 10, 19, 8, 20, 38, 65, 16, 40, 76, 130, 211, 32, 80, 152, 260, 422, 665, 64, 160, 304, 520, 844, 1330, 2059, 128, 320, 608, 1040, 1688, 2660, 4118, 6305, 256, 640, 1216, 2080, 3376, 5320, 8236, 12610, 19171
Offset: 0

Views

Author

Christopher Tompkins, Nov 18 2013

Keywords

Comments

Generated from Running Total of each row of A036561.
Left edge is A000079 (offset 0): (1, 2, 4, 8, 16, 32, 64, ...)
Right edge is A001047 (offset 1): (1, 5, 19, 65, 211, 665, ...)
Row sums are A066810 (offset 2): (1, 7, 33, 131, 473, 1611, ...)

Examples

			The start of the sequence as a triangle read by rows:
  1;
  2,  5;
  4,  10, 19;
  8,  20, 38,  65;
  16, 40, 76,  130, 211;
  32, 80, 152, 260, 422, 665;
  ...
		

Crossrefs

Programs

  • Mathematica
    T[n_,k_]:=Sum[3^j*2^(n-j),{j,0,k}];Flatten[Table[T[n,k],{n,0,8},{k,0,n}]] (* Detlef Meya, Dec 20 2023 *)

Formula

T(n,k) = Sum_{j=0..k} 3^j*2^(n-j). - Detlef Meya, Dec 20 2023
T(n,k) = 2^n*(3*(3/2)^k-2). - Alois P. Heinz, Dec 20 2023