OFFSET
0,3
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..112
FORMULA
a(n) = mod(binomial(n+1,2), 2)*A183895(n).
MATHEMATICA
Table[((-1)^Floor[(n+1)/2] -1)*2^(Floor[n*(n+1)/4] -1), {n, 0, 30}] (* G. C. Greubel, Mar 23 2024 *)
PROG
(Magma) [((-1)^Floor((n+1)/2) -1)*2^Floor((n^2+n-4)/4): n in [0..30]]; // G. C. Greubel, Mar 23 2024
(SageMath) [((-1)^((n+1)//2) -1)*2^(n*(n+1)//4 -1) for n in range(31)] # G. C. Greubel, Mar 23 2024
CROSSREFS
KEYWORD
sign
AUTHOR
Paul Barry, Jan 07 2011
STATUS
approved