A161341 First differences of A161340.

1, 26, 56, 260, 56, 392, 392, 2192, 56, 392, 392, 2744, 392, 2744, 2744, 16952, 56, 392, 392, 2744, 392, 2744, 2744, 19208, 392, 2744, 2744, 19208, 2744, 19208, 19208, 125336, 56, 392, 392, 2744, 392, 2744, 2744, 19208, 392, 2744, 2744, 19208, 2744, 19208, 19208

Offset: 1

Author

Omar E. Pol, Jun 14 2009

Keywords

• nonn
• tabf

Examples

			From _Omar E. Pol_, Mar 15 2020: (Start)
Written as an irregular triangle in which row lengths give A011782 the sequence begins:
1;
26;
56, 260;
56, 392, 392, 2192;
56, 392, 392, 2744, 392, 2744, 2744, 16952;
56, 392, 392, 2744, 392, 2744, 2744, 19208, 392, 2744, 2744, 19208, 2744, ...
(End)
		

Crossrefs

Cf. A011782, A160414, A161340, A161415.

Programs

PARI

f(n) = 8*7^hammingweight(n-1); \\ A160429
ispow2(n) = my(k); (n==2) || (ispower(n,,&k) && (k==2));
a(n) = if (n==1, 1, if (ispow2(n), f(n) - 3*n*(3*n - 1), f(n))); \\ Michel Marcus, Mar 15 2020

Formula

a(n) = A160429(n) for n>1 and n not a power of 2.

a(n) = A160429(n) - 3n*(3n - 1) for n>1 and n a power of 2.

Extensions

Formula and more terms from Nathaniel Johnston, Nov 15 2010

More terms from Jinyuan Wang, Mar 14 2020