OFFSET
0,3
COMMENTS
Row sums of number triangle A115633.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..5000
Index entries for linear recurrences with constant coefficients, signature (0,1).
FORMULA
a(n) = 4*0^n - 3*(1 + (-1)^n)/2.
a(n) = Sum_{k=0..n} A115633(n, k).
From G. C. Greubel, Nov 23 2021: (Start)
a(n) = 1 if n = 0, otherwise a(n) = -A010674(n-1).
E.g.f.: 4 - 3*cosh(x). (End)
MATHEMATICA
Join[{1}, -3*Mod[Range[100] -1, 2]] (* G. C. Greubel, Nov 23 2021 *)
PROG
(Magma) [4*0^n -3*(1+(-1)^n)/2: n in [0..100]]; // G. C. Greubel, Nov 23 2021
(Sage) [1]+[-3*((n-1)%2) for n in (1..100)] # G. C. Greubel, Nov 23 2021
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Jan 27 2006
STATUS
approved