A159407 Number of n X n arrays of squares of integers summing to 21.

28, 7182, 3923136, 2168352600, 1094602264164, 437181997913808, 123598365410489088, 22732655012770729752, 2620728473996336526900, 193309311936589609598244, 9610726322148658419480768, 340892034159072851206852178, 9072999131907316862007475724

Offset

2,1

Comments

All such sequences have holonomic recurrences (cf. comment in A159359). - Georg Fischer, Feb 17 2022

Links

R. H. Hardin, Table of n, a(n) for n = 2..100

Vaclav Kotesovec, G.f. for A159407

Index entries for linear recurrences with constant coefficients, signature (43, -903, 12341, -123410, 962598, -6096454, 32224114, -145008513, 563921995, -1917334783, 5752004349, -15338678264, 36576848168, -78378960360, 151532656696, -265182149218, 421171648758, -608359048206, 800472431850, -960566918220, 1052049481860, -1052049481860, 960566918220, -800472431850, 608359048206, -421171648758, 265182149218, -151532656696, 78378960360, -36576848168, 15338678264, -5752004349, 1917334783, -563921995, 145008513, -32224114, 6096454, -962598, 123410, -12341, 903, -43, 1).

Formula

G.f.: see link above. - Vaclav Kotesovec, Dec 04 2012

Crossrefs

Sequence in context: A221935 A230268 A203328 * A099058 A281128 A222018

Adjacent sequences: A159404 A159405 A159406 * A159408 A159409 A159410

Keyword

nonn

Author

R. H. Hardin, Apr 11 2009

Status

approved