A277046 Triangle read by rows: T(n,k) = 2^n - n + k - 1 for n >= 1, with 1 <= k <= 2n-1.

1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17, 18, 27, 28, 29, 30, 31, 32, 33, 34, 35, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 503, 504, 505, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519

Offset: 1

Author

Miquel Cerda, Sep 27 2016

Keywords

• nonn
• tabf

Examples

			Triangle begins:
1;
2,   3,  4;
5,   6,  7,  8,  9;
12, 13, 14, 15, 16, 17, 18;
27, 28, 29, 30, 31, 32, 33, 34, 35;
58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68;
...
Written as an isosceles triangle the sequence begins:
.                      1;
.                  2,  3,  4;
.              5,  6,  7,  8,  9;
.         12, 13, 14, 15, 16, 17, 18;
.     27, 28, 29, 30, 31, 32, 33, 34, 35;
. 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68;
..
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Row lengths are A005408.

Row sums give A118414.

Column 1 gives A000325, n>=1.

Middle diagonal gives A000225.

Right border gives A083706.

Cf. A118413.

Programs

Mathematica

Table[2^n-n+k-1,{n,10},{k,2n-1}]//Flatten (* Harvey P. Dale, Nov 27 2021 *)

Extensions

Definition from Omar E. Pol, Sep 28 2016