OFFSET
0,2
COMMENTS
a(n) is the determinant of the symmetric matrix (if(j<=floor((i+j)/2), 2^k*(k+1), 2^n*(n+1)))_{0<=i,j<=n}.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..77
FORMULA
a(n) = 2^binomial(n,2)*A001710(n+2).
a(n) = 2^binomial(n+1,2)*Product_{k=0..n} (k+2)/2 = Product_{k=0..n} 2^k*(k+2)/2.
EXAMPLE
a(3)=280 since det[1, 1, 1, 1; 1, 4, 4, 4; 1, 4, 12, 12; 1, 4, 12, 32]=280.
MATHEMATICA
Table[2^((n^2 - n - 2)/2)*(n + 2)!, {n, 0, 50}] (* G. C. Greubel, Jul 23 2017 *)
PROG
(PARI) for(n=0, 50, print1(2^((n^2 - n - 2)/2)*(n + 2)!, ", ")) \\ G. C. Greubel, Jul 23 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Feb 16 2011
STATUS
approved