OFFSET
1,3
LINKS
FORMULA
a(n) = Sum_{k=2..n-1} (floor(3^(2n+1)/2^(2k+3)-7/8) + 1).
MATHEMATICA
a[n_]:=Sum[Floor[3^(2n+1)/2^(2k+3)-7/8]+1, {k, 2, n-1}];
Table[a[n], {n, 21}]
CROSSREFS
KEYWORD
nonn
AUTHOR
XU Pingya, Nov 27 2018
STATUS
approved