A157794 a(n) = term (1,1) in M^n * [1,0,0,0,...]; M = parity check matrix for the binary Golay code.

1, 5, 40, 259, 1727, 11677, 78887, 532826, 3599266, 24313336, 164238089, 1109439854, 7494345348, 50624835011, 341974359592

Offset

1,2

Comments

a(n)/a(n-1) tends to 6.7550711321...

References

Mathworld, Golay Code

Links

Table of n, a(n) for n=1..15.

Formula

a(n) = term (1,1) in M^n * [1,0,0,0,...]; M = parity check matrix for the binary Golay code.

Example

M = the 11 by 12 matrix:
1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1;
1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1;
1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0;
1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0;
1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0;
1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1;
1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0;
1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0;
1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1;
1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1;
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
a(3) = 40 = term (1,1) in M^3.

Crossrefs

Sequence in context: A269822 A043019 A054604 * A001656 A087632 A229279

Adjacent sequences: A157791 A157792 A157793 * A157795 A157796 A157797

Keyword

nonn

Author

Gary W. Adamson & Roger L. Bagula, Mar 07 2009

Status

approved