A271709 Table T(n,k) = 2^n + 2^k read by antidiagonals.

2, 3, 3, 5, 4, 5, 9, 6, 6, 9, 17, 10, 8, 10, 17, 33, 18, 12, 12, 18, 33, 65, 34, 20, 16, 20, 34, 65, 129, 66, 36, 24, 24, 36, 66, 129, 257, 130, 68, 40, 32, 40, 68, 130, 257, 513, 258, 132, 72, 48, 48, 72, 132, 258, 513, 1025, 514, 260, 136, 80, 64, 80, 136

Offset: 0

Author

Peter Kagey, Apr 12 2016

Keywords

• nonn
• tabl
• easy

Comments

n > 1 is in this sequence if and only if it is in A018900 or A000079.

Examples

			a(0) = T(0, 0) = 2^0 + 2^0 = 2
a(1) = T(1, 0) = 2^1 + 2^0 = 3
   2,   3,   5,   9,  17,  33,  65, 129, 257, 513,1025,
   3,   4,   6,  10,  18,  34,  66, 130, 258, 514,1026,
   5,   6,   8,  12,  20,  36,  68, 132, 260, 516,1028,
   9,  10,  12,  16,  24,  40,  72, 136, 264, 520,1032,
  17,  18,  20,  24,  32,  48,  80, 144, 272, 528,1040,
  33,  34,  36,  40,  48,  64,  96, 160, 288, 544,1056,
  65,  66,  68,  72,  80,  96, 128, 192, 320, 576,1088,
 129, 130, 132, 136, 144, 160, 192, 256, 384, 640,1152,
 257, 258, 260, 264, 272, 288, 320, 384, 512, 768,1280,
 513, 514, 516, 520, 528, 544, 576, 640, 768,1024,1536,
1025,1026,1028,1032,1040,1056,1088,1152,1280,1536,2048,
		

Links

• Peter Kagey, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A173786, A271710.

Programs

Maple

A271709 := proc(n,k)
    2^n+2^k ;
end proc: # R. J. Mathar, Apr 15 2016

Mathematica

Table[2^(n - k) + 2^k, {n, 0, 10}, {k, 0, n}] // Flatten (* Michael De Vlieger, Apr 12 2016 *)

PARI

T(n, k) = 2^n + 2^k;
matrix(10, 10, n, k, n--;k--;T(n,k)) \\ Michel Marcus, Apr 12 2016

Formula

T(n,k) = T(k,n) = A173786(n,k). - R. J. Mathar, Apr 15 2016