A131772 Partial sums (A131771) equal this sequence excluding zeros located at positions {m*(m+1)/2, m>=0}, with a(0)=1.

1, 0, 1, 2, 0, 4, 4, 8, 0, 12, 20, 20, 32, 0, 52, 72, 104, 104, 156, 0, 228, 332, 436, 592, 592, 820, 0, 1152, 1588, 2180, 2772, 3592, 3592, 4744, 0, 6332, 8512, 11284, 14876, 18468, 23212, 23212, 29544, 0, 38056, 49340, 64216, 82684, 105896, 129108, 158652

Offset

0,4

Links

Table of n, a(n) for n=0..50.

Example

Partial sums (A131771) begin:
[1,1,2,4,4,8,12,20,20,32,52,72,104,104,156,228,332,436,592,...].
Second partial sums (A131770) begin:
[1,2,4,8,12,20,32,52,72,104,156,228,332,436,592,...].

Prog

(PARI)

Crossrefs

Cf. A131770, A131771 (partial sums).

Sequence in context: A360133 A057377 A145811 * A363524 A304877 A147980

Adjacent sequences: A131769 A131770 A131771 * A131773 A131774 A131775

Keyword

nonn

Author

Paul D. Hanna, Jul 14 2007

Status

approved