A089941 Row sums of triangle A089940.

1, 2, 4, 9, 19, 42, 90, 197, 424, 923, 1989, 4315, 9300, 20129, 43374, 93724, 201888, 435713, 938218, 2022972, 4354569, 9382489, 20190181, 43477688, 93534469, 201326672, 433017364, 931701321, 2003520121, 4309597827, 9265723250

Offset

0,2

Links

Table of n, a(n) for n=0..30.

Formula

a(n)=sum{k=0..n, Bin(n+k, floor((n-k)/2))}.

Conjecture: +n*(n+6)*(n-5)*a(n) -(n+6)*(n^2-3*n-6)*a(n-1) -2*(n+6)*(3*n^2-20*n

+27)*a(n-2) +(n+6)*(3*n^2-19*n+36)*a(n-3) +2*(4*n-15)*(n-3)*(n+6)*a(n-4) +4*(n-3

)*(n-4)*(n+6)*a(n-5)=0. - R. J. Mathar, Dec 10 2014

Crossrefs

Sequence in context: A275862 A036622 A001384 * A307464 A127681 A192923

Adjacent sequences: A089938 A089939 A089940 * A089942 A089943 A089944

Keyword

easy,nonn

Author

Paul Barry, Nov 16 2003

Status

approved