OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,0,0,0,0,1,-1).
FORMULA
a(n) = a(n-1) + a(n-13) - a(n-14) for n > 13.
a(n) = Sum_{i=1..n} (-1)^floor((2*i-2)/13).
MATHEMATICA
Table[Sum[(-1)^Floor[(2 i - 2)/13], {i, n}], {n, 0, 100}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, May 29 2017
STATUS
approved