|
| |
|
|
A074330
|
|
a(n)=sum(k=1,n,2^b(k)) where b(k) denotes the number of 1's in the binary representation of k.
|
|
3
| |
|
|
2, 4, 8, 10, 14, 18, 26, 28, 32, 36, 44, 48, 56, 64, 80, 82, 86, 90, 98, 102, 110, 118, 134, 138, 146, 154, 170, 178, 194, 210, 242, 244, 248, 252, 260, 264, 272, 280, 296, 300, 308, 316, 332, 340, 356, 372, 404, 408, 416, 424, 440, 448, 464, 480, 512, 520, 536
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
FORMULA
| a(n+1)-a(n) = A001316(n)
a(0)=0, a(2n) = 2a(n-1) + a(n) + 2, a(2n+1) = 3a(n) + 2. G.f. 1/(1-x) * prod(k>=0, 1 + 2x^2^k). - Ralf Stephan (ralf(AT)ark.in-berlin.de), Oct 07 2003
|
|
|
PROG
| (PARI) a(n)=sum(i=1, n, 2^sum(k=1, length(binary(i)), component(binary(i), k)))
|
|
|
CROSSREFS
| a(n) = A006046(n+1)-1. Cf. A080263.
Sequence in context: A034822 A050567 A069879 * A024895 A087915 A088967
Adjacent sequences: A074327 A074328 A074329 * A074331 A074332 A074333
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 06 2002
|
| |
|
|
