OFFSET
0,2
REFERENCES
A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (9,-36,84,-126,126,-84,36,-9,1).
FORMULA
a(n) = binomial(n+7, 7)*(3n+8)/8.
G.f.: (1+2*x)/(1-x)^9.
MATHEMATICA
LinearRecurrence[{9, -36, 84, -126, 126, -84, 36, -9, 1}, {1, 11, 63, 255, 825, 2277, 5577, 12441, 25740}, 30] (* or *) Table[(3*n+8)* Binomial[n+7, 7]/8, {n, 0, 30}] (* G. C. Greubel, May 25 2018 *)
PROG
(PARI) a(n)=binomial(n+7, 7)*(3*n+8)/8 \\ Charles R Greathouse IV, Oct 07 2015
(Magma) [(3*n+8)*Binomial(n+7, 7)/8: n in [0..30]]; // G. C. Greubel, May 25 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Barry E. Williams, Jan 06 2000
EXTENSIONS
Terms a(24) onward added by G. C. Greubel, May 25 2018
STATUS
approved