OFFSET
0,5
COMMENTS
Number of partitions of n into parts 1, 4, 5 and 7. - Ilya Gutkovskiy, May 17 2017
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,0,-1,1,-1,-1,1,-1,0,1,0, 0,1,-1).
FORMULA
a(n) = floor((2*n^3+51*n^2+388*n+1680)/1680). - Tani Akinari, May 23 2014
a(-17 - n) = -a(n). - Michael Somos, May 23 2014
EXAMPLE
G.f. = 1 + x + x^2 + x^3 + 2*x^4 + 3*x^5 + 3*x^6 + 4*x^7 + 5*x^8 + 6*x^9 + ...
MATHEMATICA
a[ n_] := Quotient[ 2 n^3 + 51 n^2 + 388 n, 1680] + 1; (* Michael Somos, May 23 2014 *)
CoefficientList[Series[1/((1 - x)*(1 - x^4)*(1 - x^5)*(1 - x^7)), {x, 0, 50}], x] (* G. C. Greubel, May 17 2017 *)
PROG
(PARI) {a(n) = (2*n^3 + 51*n^2 + 388*n) \ 1680 + 1}; /* Michael Somos, May 23 2014 */
(PARI) x='x+O('x^50); Vec(1/((1 - x)*(1 - x^4)*(1 - x^5)*(1 - x^7))) \\ G. C. Greubel, May 17 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 11 1999
STATUS
approved