A191355 Indices of terms in A069748 with two decimal digits 1 and all others 0.

5, 6, 8, 9, 12, 15, 18, 22, 27, 31, 37, 43, 49, 56, 64, 71, 80, 89, 98, 108

Offset

1,1

Links

Table of n, a(n) for n=1..20.

Formula

Conjectural formula: a(n) = 5 + Sum_{i=1..n-1} A105637(i).

Equivalent conjecture: a(n) = -(-1)^n/8 + A049347(n)/3 + 115/24 + n/6 + n^2/4. - R. J. Mathar, Jul 11 2011

Crossrefs

Cf. A002780, A069748, A105637.

Sequence in context: A120174 A184817 A347872 * A337143 A047439 A095763

Adjacent sequences: A191352 A191353 A191354 * A191356 A191357 A191358

Keyword

nonn,base,more

Author

Vladimir Shevelev, May 31 2011

Extensions

a(18)-a(20), using A002780 b-file, added by Michel Marcus, Apr 17 2023

Status

approved