A167385 a(n)= sum_{i=7..n+6} A000931(i).

1, 3, 5, 8, 12, 17, 24, 33, 45, 61, 82, 110, 147, 196, 261, 347, 461, 612, 812, 1077, 1428, 1893, 2509, 3325, 4406, 5838, 7735, 10248, 13577, 17987, 23829, 31568, 41820, 55401, 73392, 97225, 128797, 170621, 226026, 299422, 396651, 525452, 696077, 922107, 1221533

Offset

0,2

Links

Table of n, a(n) for n=0..44.

Formula

a(n+1)/a(n)-> A060005 as n->infinity.

G.f.: (1+x)^2/((x-1)*(x^3+x^2-1)). a(n)= +a(n-1) +a(n-2) -a(n-4). [Nov 05 2009]

a(n) = A000931(n+12)-4. [Nov 05 2009]

Mathematica

Clear[f, g, n]
f[0] = 0; f[1] = 1; f[2] = 1; f[n_] := f[n] = f[n - 2] + f[n - 3];
g[n_] := Sum[f[i + 3], {i, 0, n}]
Table[g[n], {n, 0, 30}]

Crossrefs

Cf. A018917.

Sequence in context: A238531 A038088 A018917 * A265061 A265062 A265063

Adjacent sequences: A167382 A167383 A167384 * A167386 A167387 A167388

Keyword

nonn,easy

Author

Roger L. Bagula, Nov 02 2009

Extensions

Notation normalized, definition corrected, g.f. added - The Assoc. Editors of the OEIS, Nov 05 2009

Status

approved