OFFSET
0,7
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,-1,0,0,0,0,0,0,0,0,0,0,1,-2,1).
FORMULA
From R. J. Mathar, Apr 15 2010: (Start)
a(n) = 2*a(n-1) - a(n-2) + a(n-13) - 2*a(n-14) + a(n-15).
G.f.: x^5*(1+x^6)/(1+x*(-2+x*(1+x^11*(-1+(2-x)*x)))). (End)
MATHEMATICA
Table[Floor[(n(n-1))/13], {n, 0, 70}] (* or *) LinearRecurrence[{2, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, 1}, {0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14}, 70] (* Harvey P. Dale, Nov 10 2019 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved