A103488 a(n) = 2^(n^2-1).

1, 8, 256, 32768, 16777216, 34359738368, 281474976710656, 9223372036854775808, 1208925819614629174706176, 633825300114114700748351602688, 1329227995784915872903807060280344576, 11150372599265311570767859136324180752990208

Offset: 1

Author

Zerinvary Lajos, Jul 30 2006

Keywords

• easy
• nonn

Comments

From the classic story: number of grains of wheat on last square of n X n chessboard.

Hankel transform of A059304 and of A084771. - Philippe Deléham, Dec 02 2007

The number of compositions of n^2. - Alois P. Heinz, Feb 22 2020

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..50
• Peter Kagey and William Keehn, Counting Tilings of the n X m Grid, Cylinder, and Torus, J. Int. Seq. (2024) Vol. 27, Art. No. 24.6.1. See section A, pp. 6, 10.

Crossrefs

Cf. A000079, A000290, A005563, A011782.

Programs

Magma

[2^(n^2-1): n in [1..15]]; // Vincenzo Librandi, Feb 25 2014

Maple

[seq(2^(n^2-1),n=1..14)];

Mathematica

Table[2^(n^2 - 1), {n, 1, 20}] (* Vincenzo Librandi, Feb 25 2014 *)

PARI

a(n) = 2^(n^2-1); \\ Joerg Arndt, Feb 23 2014

Formula

a(n) = A000079(A005563(n-1)). - Michel Marcus, Feb 25 2014

a(n) = A011782(A000290(n)). - Alois P. Heinz, Feb 22 2020