OFFSET
0,2
LINKS
Matthias Beck, The number of "magic" squares and hypercubes, arXiv:math/0201013 [math.CO], 2002-2005.
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
G.f.: (1+x)*(1+20*x+70*x^2+20*x^3+x^4)/(1-x)^7. [corrected by Colin Barker, Aug 10 2012]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Apr 22 2004
STATUS
approved