A212739 a(n) = 2^(n^2) - 1.

0, 1, 15, 511, 65535, 33554431, 68719476735, 562949953421311, 18446744073709551615, 2417851639229258349412351, 1267650600228229401496703205375, 2658455991569831745807614120560689151, 22300745198530623141535718272648361505980415

Offset

0,3

Comments

Number of grains for squared chessboards.

Links

Table of n, a(n) for n=0..12.

Wikipedia, Wheat and chessboard problem

Formula

a(n) = 2^(n^2) - 1 = A002416(n) - 1. - Omar E. Pol, Jun 11 2012

Example

For usual 8 X 8 chessboard there are 2^64 - 1 = 18446744073709551615 grains.

Maple

a:= n-> 2^(n^2)-1:
seq(a(n), n=0..15);

Crossrefs

Cf. A000225, A002416.

Sequence in context: A218280 A218632 A218235 * A009068 A268960 A157166

Adjacent sequences: A212736 A212737 A212738 * A212740 A212741 A212742

Keyword

nonn

Author

Jani Melik, Jun 06 2012

Extensions

Better name from Omar E. Pol, Jun 11 2012

Status

approved