A144631 Second diagonal (or column) of A144630.

4, 12, 880, 46900, 1615824, 45094896, 1115345088, 25519125060, 553014576400, 11514200107696, 232490008680384, 4581732884262352, 88532684825838400, 1683073282734360000, 31561148509363526400, 584964180982546208100

Offset

2,1

Links

Klaus Brockhaus, Table of n, a(n) for n=2..100

Maple

invH := proc(n, i, j) (-1)^(i+j)*(i+j-1)*binomial(n+i-1, n-j)*binomial(n+j-1, n-i)* (binomial(i+j-2, i-1))^2 ; end: A144630 := proc(n, k) local T, i, j ; T := 0 ; for i from n-k+1 to n do for j from n-k+1 to n do T := T+invH(n, i, j) ; od; od; RETURN(T) ; end: A144631 := proc(n) A144630(n+1, 2) ; end: for n from 1 to 20 do printf("%a, ", A144631(n)) : od: # R. J. Mathar, Jan 21 2009

Prog

(Magma) [ [ &+[I[i][j]: i, j in [k..n] ]: k in [n..1 by -1] ][2] where I:=H^-1 where H:=Matrix(Rationals(), n, n, [ < i, j, 1/(i+j-1) >: i, j in [1..n] ] ): n in [2..17] ]; // Klaus Brockhaus, Jan 22 2009

Crossrefs

Sequence in context: A299808 A085116 A104129 * A009516 A266500 A146210

Adjacent sequences: A144628 A144629 A144630 * A144632 A144633 A144634

Keyword

nonn

Author

Daniel McLaury and Ben Golub, Jan 20 2009

Extensions

More terms from R. J. Mathar and Klaus Brockhaus, Jan 21 2009

Status

approved