A288349 Partial sums of A059268.

1, 2, 4, 5, 7, 11, 12, 14, 18, 26, 27, 29, 33, 41, 57, 58, 60, 64, 72, 88, 120, 121, 123, 127, 135, 151, 183, 247, 248, 250, 254, 262, 278, 310, 374, 502, 503, 505, 509, 517, 533, 565, 629, 757, 1013, 1014, 1016, 1020, 1028, 1044, 1076, 1140, 1268, 1524, 2036

Offset: 1

Author

Zhining Yang, Jun 08 2017

Keywords

• nonn

Examples

			For n=10, a(10) = 1 + 1 + 2 + 1 + 2 + 4 + 1 + 2 + 4 + 8 = 26.
		

Crossrefs

Cf. A059268.

Programs

Mathematica

Accumulate@ Flatten@ Array[2^Range[0, #] &, 10, 0] (* Michael De Vlieger, Jun 11 2017 *)

PARI

for(n=1, 100, t=floor(sqrt(2*n)+1/2); print1(2^t+2^(n-t*(t-1)/2)-t-2, ", "));

Formula

a(n) = 2^t + 2^(n-t*(t-1)/2) - t - 2, where t = floor(sqrt(2*n) + 1/2), n>=1.