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

Author

Clark Kimberling

Keywords

• nonn

Links

• 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

Crossrefs

Cf. A026375, A026378.

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.