A059511 Main diagonal of the array A059217.

1, 3, 26, 471, 13953, 627421, 39873948, 3406344237, 376591685322, 52319828460127, 8922977163384085, 1832831375530080986, 446306812127457163805, 127130280682997045232005, 41881054710966221044222595, 15800074329058136531647698779

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..240

Mathematica

t[0, 0] = 1; t[0, _?EvenQ] = 1; t[_?OddQ, 0] = 1; t[n_, k_] /; OddQ[n + k](*up*):= t[n, k] = t[n + 1, k - 1] + Sum[t[n, j], {j, 0, k - 1}];
t[n_, k_] /; EvenQ[n + k](*down*):= t[n, k] = t[n - 1, k + 1] + Sum[t[j, k], {j, 0, n - 1}]; Table[t[n, n], {n, 0, 50}] (* G. C. Greubel, Sep 10 2017 *)

Crossrefs

Sequence in context: A274778 A049088 A089041 * A112676 A103112 A064941

Adjacent sequences: A059508 A059509 A059510 * A059512 A059513 A059514

Keyword

easy,nonn

Author

Floor van Lamoen, Jan 21 2001

Extensions

Terms a(11) onward added by G. C. Greubel, Sep 10 2017

Status

approved