A026380 a(n) = T(n,[ n/2 ]), where T is the array in A026374.

1, 3, 4, 11, 17, 45, 75, 195, 339, 873, 1558, 3989, 7247, 18483, 34016, 86515, 160795, 408105, 764388, 1936881, 3650571, 9238023, 17501619, 44241261, 84179877, 212601015, 406020930, 1024642875, 1963073865, 4950790605

Offset

0,2

Links

Table of n, a(n) for n=0..29.

D. E. Davenport, L. W. Shapiro and L. C. Woodson, The Double Riordan Group, The Electronic Journal of Combinatorics, 18(2) (2012), #P33. - From N. J. A. Sloane, May 11 2012

Formula

a(2n)=A026378(n+1), a(2n-1)=A026375(n). - Emeric Deutsch, Feb 18 2004

a(2n) = A026378(2n+1), a(2n+1) = A026375(n+1).

Davenport et al. give a g.f.

Crossrefs

Cf. A026375, A026378.

Sequence in context: A231882 A026753 A027222 * A030225 A339157 A060285

Adjacent sequences: A026377 A026378 A026379 * A026381 A026382 A026383

Keyword

nonn

Author

Clark Kimberling

Status

approved