A036565 Triangle of numbers in which i-th row is {2^(i-j)*7^j, 0<=j<=i}; i >= 0.

1, 2, 7, 4, 14, 49, 8, 28, 98, 343, 16, 56, 196, 686, 2401, 32, 112, 392, 1372, 4802, 16807, 64, 224, 784, 2744, 9604, 33614, 117649, 128, 448, 1568, 5488, 19208, 67228, 235298, 823543, 256, 896, 3136, 10976, 38416, 134456, 470596, 1647086, 5764801

Offset

0,2

Links

Table of n, a(n) for n=0..44.

Formula

G.f.: 1/((1 - 2*x)(1 - 7*x*y)). - Ilya Gutkovskiy, Jun 03 2017

Example

The triangle begins as:
  1;
  2,  7;
  4, 14, 49;
  8, 28, 98, 343;
  ...

Mathematica

row[n_] := Table[SeriesCoefficient[1/((1 - 2*x)(1 - 7*x*y)), {x, 0, i}, {y, 0, j}], {i, n, n}, {j, 0, n}]; Array[row, 9, 0]//Flatten (* Stefano Spezia, Aug 19 2025 *)

Crossrefs

Cf. A003591.

Cf. A000079 (1st column), A000420 (diagonal), A016130 (row sums).

Sequence in context: A102514 A115857 A065621 * A054787 A190716 A303384

Adjacent sequences: A036562 A036563 A036564 * A036566 A036567 A036568

Keyword

nonn,easy,tabl

Author

N. J. A. Sloane

Status

approved