A038810 a(n) is the number of ways to write the number n as dk...di...d2d1d0 where digit di represents di * (di+1)^i, restricting di to 0..9.

1, 1, 2, 2, 3, 3, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 9, 9, 11, 11, 13, 13, 13, 13, 15, 15, 16, 16, 17, 17, 17, 17, 19, 19, 19, 19, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 24, 24, 25, 25, 27, 27, 26, 26, 30, 30, 32, 32, 33, 33, 36, 36, 39, 39, 39, 39, 38, 38, 39, 39, 39, 39, 42, 42, 44

Offset

0,3

Links

Table of n, a(n) for n=0..74.

Example

a(7)=5 since 7 = (7*8^0) = (1*2^1)+(5*6^0) = (2*3^1)+(1*2^0) = (1*2^2)+(0*1^1)+(3*4^0) = (1*2^2)+(1*2^1)+(1*2^0), which are the numbers {7,15,21,103,111}.

Crossrefs

Sequence in context: A099961 A286107 A285735 * A350350 A178503 A211275

Adjacent sequences: A038807 A038808 A038809 * A038811 A038812 A038813

Keyword

nonn,base

Author

Naohiro Nomoto

Extensions

More terms and additional comments from Larry Reeves (larryr(AT)acm.org), Mar 16 2001.

Status

approved