OFFSET
0,11
COMMENTS
Number of partitions of n into parts 3, 5, and 7. - Joerg Arndt, Aug 17 2013
Number of different total numbers of kicks, tries and converted tries which lead to a score of n in a rugby (union) match. - Matthew Scroggs, Jul 09 2015
REFERENCES
L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 114, [6t].
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 230
M. Janjic, On Linear Recurrence Equations Arising from Compositions of Positive Integers, Journal of Integer Sequences, Vol. 18 (2015), Article 15.4.7.
Index entries for linear recurrences with constant coefficients, signature (0,0,1,0,1,0,1,-1,0,-1,0,-1,0,0,1).
FORMULA
a(n) = a(n-3) + a(n-5) + a(n-7) - a(n-8) - a(n-10) - a(n-12) + a(n-15) for n >= 15. - David Neil McGrath, Sep 03 2014
G.f.: 1 / ((1 - x^3) * (1 - x^5) * (1 - x^7)).
Euler transform of length 7 sequence [ 0, 0, 1, 0, 1, 0, 1]. - Michael Somos, Sep 30 2014
a(n) = a(-15-n) for all n in Z. - Michael Somos, Sep 30 2014
0 = a(n) - a(n+3) - a(n+5) + a(n+8) - [mod(n, 7) == 6] for all n in Z. - Michael Somos, Sep 30 2014
a(n) = round(n^2/210 + n/14 + 5/21) + r(n) where r(n) = 1 if n == 0, 3, 10, 15, 45, 75, 80, 87, or 90 (mod 105), r(n) = -1 if n == 4, 11, 16, 44, 46, 74, 79 or 86 (mod 105), r(n) = 0 otherwise. - Robert Israel, Jul 09 2015
EXAMPLE
G.f. = 1 + x^3 + x^5 + x^6 + x^7 + x^8 + x^9 + 2*x^10 + x^11 + 2*x^12 + ...
MAPLE
S:= series(1/((1-x^3)*(1-x^5)*(1-x^7)), x, 101):
seq(coeff(S, x, j), j=0..100); # Robert Israel, Jul 09 2015
MATHEMATICA
CoefficientList[Series[1/((1-x^3)(1-x^5)(1-x^7)), {x, 0, 100}], x] (* Vincenzo Librandi, Jun 23 2013 *)
LinearRecurrence[{0, 0, 1, 0, 1, 0, 1, -1, 0, -1, 0, -1, 0, 0, 1}, {1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2}, 70] (* Harvey P. Dale, Aug 04 2020 *)
PROG
(PARI) a(n)=[1, 0, -2, 2, -2, 0, 1][n%7+1]/7 +[2, -1, 0, 0, -1][n%5+1]/5 +[2, -1, -1][n%3+1]/9 +(3*n^2+45*n+148)/630; \\ Tani Akinari, Aug 17 2013
(PARI) a(n)=floor((n^2+15*n+86)/210+(n%3<1)/3+3*(n%5<1)/5) \\ Tani Akinari, Sep 30 2014
(Magma) R<x>:=PowerSeriesRing(Integers(), 100); Coefficients(R!( 1/((1-x^3)*(1-x^5)*(1-x^7)) )); // G. C. Greubel, Sep 08 2019
(Sage)
def A008677_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P(1/((1-x^3)*(1-x^5)*(1-x^7))).list()
A008677_list(100) # G. C. Greubel, Sep 08 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Typo in name fixed by Vincenzo Librandi, Jun 23 2013
STATUS
approved