A026021 T(n,[ n/2 ]), where T is the array defined in A026009.

1, 1, 2, 3, 6, 10, 19, 34, 62, 117, 207, 407, 704, 1430, 2431, 5070, 8502, 18122, 30056, 65246, 107236, 236436, 385662, 861764, 1396652, 3157325, 5088865, 11622015, 18642420, 42961470, 68624295, 159419670, 253706790, 593636670, 941630580

Offset

0,3

Links

Table of n, a(n) for n=0..34.

Formula

Conjecture: -(n+7)*(5*n-34)*a(n) +8*(-n-14)*a(n-1) +(27*n^2-83*n-428)*a(n-2) +8*(4*n+5)*a(n-3) 44*(n-3)*(7*n-27)*a(n-4)=0. - R. J. Mathar, Jun 20 2013

Crossrefs

Cf. A026009.

Sequence in context: A165920 A274160 A190501 * A291875 A227309 A368279

Adjacent sequences: A026018 A026019 A026020 * A026022 A026023 A026024

Keyword

nonn

Author

Clark Kimberling

Status

approved