OFFSET
1,2
LINKS
Stuart Bruff, Table of n, a(n) for n = 1..26
FORMULA
a(n) = 2^(n^2) - (1 + (2^((n+1)*(n-1)) + 2^((n+1)*(n-2) + .. 1))).
a(n) = 2^(n^2) - (1 + A119408(n)).
a(n) = ((2^(n^2) - 2)*(2^n - 1))/(2*2^n - 1)
EXAMPLE
For n = 3, a(3) = 2^(3^2) - (1 + (2^((3+1)*(3-1)) + 2^((3+1)*(3-2)) + 2^((3+1)*(3-3)))) = 2^9 - (1 + (2^8 + 2^4 + 2^0)) = 512 - (1 + (256 + 16 + 1)) = 512 - 274 = 238.
MAPLE
seq((2^(n^2)-2)*(1-2^n)/(1-2^(n+1)), n=1..26); # Robert Israel, Jun 02 2015
MATHEMATICA
Table[2^(n^2) - (1 + Sum[2^((n + 1) (n - k)), {k, n}]), {n, 12}] (* Michael De Vlieger, Jun 02 2015 *)
PROG
(Mathcad) 2^(n^2) - (1 + Summation[k=1..n (2^((n+1).(n-k)))])
(Magma) [(2^(n^2)-2)*(1-2^n)/(1-2^(n+1)): n in [1..15]]; // Vincenzo Librandi, Jun 03 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Stuart Bruff, Jun 02 2015
STATUS
approved