login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A159356 Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 4 1
9, 767, 19252, 182643, 1036981, 4279949, 14199872, 40175697, 100665373, 229182711, 482835464, 954070027, 1786340817, 3194495053, 5490736316, 9117102929, 14685469857, 23026155487, 35246287308, 52799153171, 77565837469 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

R. H. Hardin, Table of n, a(n) for n=3..34

FORMULA

Empirical (for n>=3): a(n) = 1/288*(519*n^8 - 6716*n^7 + 34142*n^6 - 78248*n^5 + 32735*n^4 + 236596*n^3 - 555412*n^2 + 518112*n - 185184). - Vaclav Kotesovec, Nov 30 2012

Empirical G.f.: -x^2 + x^2*(-1 - 722*x^2 - 12589*x^3 - 36357*x^4 - 22846*x^5 - 692*x^6 + 535*x^7 + 12*x^8)/(-1+x)^9. - Vaclav Kotesovec, Nov 30 2012

CROSSREFS

Sequence in context: A145183 A124417 A265463 * A246123 A246124 A223380

Adjacent sequences:  A159353 A159354 A159355 * A159357 A159358 A159359

KEYWORD

nonn

AUTHOR

R. H. Hardin Apr 11 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 26 23:05 EST 2020. Contains 331289 sequences. (Running on oeis4.)