A221975 Triangle read by rows of the numbers that are the sum of some consecutive Mersenne numbers A000225.

1, 3, 4, 7, 10, 11, 15, 22, 25, 26, 31, 46, 53, 56, 57, 63, 94, 109, 116, 119, 120, 127, 190, 221, 236, 243, 246, 247, 255, 382, 445, 476, 491, 498, 501, 502, 511, 766, 893, 956, 987, 1002, 1009, 1012, 1013, 1023, 1534, 1789, 1916, 1979, 2010, 2025, 2032, 2035, 2036

Offset

1,2

Links

Table of n, a(n) for n=1..55.

Formula

T(n,k) = sum_{j = n-k+1..n} 2^j - 1, n>=1, k>=1.

T(n,n) = A000295(n+1).

Example

Triangle begins:
1;
3,     4;
7,    10,  11;
15,   22,  25,  26;
31,   46,  53,  56,  57;
63,   94, 109, 116, 119, 120;
127, 190, 221, 236, 243, 246, 247;
255, 382, 445, 476, 491, 498, 501, 502;
...

Crossrefs

Column 1 is A000225. Right border gives the positive terms of A000295.

Cf. A023758, A141419, A194939.

Sequence in context: A334469 A228854 A257508 * A340603 A137294 A282573

Adjacent sequences: A221972 A221973 A221974 * A221976 A221977 A221978

Keyword

nonn,tabl

Author

Omar E. Pol, Feb 12 2013

Status

approved