A070992 Partial sums of A002487.

1, 3, 4, 7, 9, 12, 13, 17, 20, 25, 27, 32, 35, 39, 40, 45, 49, 56, 59, 67, 72, 79, 81, 88, 93, 101, 104, 111, 115, 120, 121, 127, 132, 141, 145, 156, 163, 173, 176, 187, 195, 208, 213, 225, 232, 241, 243, 252, 259, 271, 276, 289, 297, 308, 311, 321, 328, 339, 343, 352, 357

Offset

0,2

Links

Table of n, a(n) for n=0..60.

Formula

a(2n) = a(n-2)+2a(n-1)+2, a(2n+1) = 2a(n-1)+a(n)+2. - Ralf Stephan, Oct 08 2003

Prog

(PARI) a(n)=if(n<2, if(n<1, 1, 3), if(n%2==0, if(n==2, 4, a(n/2-2)+2*a(n/2-1)+2), 2*a((n-3)/2)+a((n-1)/2)+2))

Crossrefs

Sequence in context: A329963 A198772 A185256 * A246514 A060142 A049844

Adjacent sequences: A070989 A070990 A070991 * A070993 A070994 A070995

Keyword

nonn

Author

N. J. A. Sloane, May 24 2002

Status

approved