A130127 Triangle defined by A000012 * A130125, read by rows.

1, 1, 2, 2, 2, 4, 2, 4, 4, 8, 3, 4, 8, 8, 16, 3, 6, 8, 16, 16, 32, 4, 6, 12, 16, 32, 32, 64, 4, 8, 12, 24, 32, 64, 64, 128, 5, 8, 16, 24, 48, 64, 128, 128, 256, 5, 10, 16, 32, 48, 96, 128, 256, 256, 512, 6, 10, 20, 32, 64, 96, 192, 256, 512, 512, 1024, 6, 12, 20, 40, 64, 128, 192, 384, 512, 1024, 1024, 2048

Offset

1,3

Comments

Row sums = A011377: (1, 3, 8, 18, 39, ...). A130126 = A130125 * A000012.

Links

G. C. Greubel, Rows n = 1..100 of triangle, flattened

Formula

T(n,k) = 2^(k-1) * floor((n-k+2)/2). - G. C. Greubel, Jun 06 2019

Example

First few rows of the triangle:
  1;
  1, 2;
  2, 2,  4;
  2, 4,  4,  8;
  3, 4,  8,  8, 16;
  3, 6,  8, 16, 16, 32;
  4, 6, 12, 16, 32, 32, 64;
  ...

Mathematica

Table[2^(k-1)*Floor[(n-k+2)/2], {n, 1, 12}, {k, 1, n}]//Flatten (* G. C. Greubel, Jun 06 2019 *)

Prog

(PARI) {T(n, k) = 2^(k-1)*floor((n-k+2)/2)}; \\ G. C. Greubel, Jun 06 2019
(Magma) [[2^(k-1)*Floor((n-k+2)/2): k in [1..n]]: n in [1..12]]; // G. C. Greubel, Jun 06 2019
(Sage) [[2^(k-1)*floor((n-k+2)/2) for k in (1..n)] for n in (1..12)] # G. C. Greubel, Jun 06 2019

Crossrefs

Cf. A000012, A130125, A130126, A011377.

Sequence in context: A368548 A240039 A369902 * A366771 A217982 A184727

Adjacent sequences: A130124 A130125 A130126 * A130128 A130129 A130130

Keyword

nonn,tabl

Author

Gary W. Adamson, May 11 2007

Extensions

More terms added by G. C. Greubel, Jun 06 2019

Status

approved