A206456 Number of 0..n arrays of length n+2 avoiding the consecutive pattern 0..n.

4, 75, 1016, 15615, 279924, 5764787, 134217712, 3486784383, 99999999980, 3138428376699, 106993205379048, 3937376385699263, 155568095557812196, 6568408355712890595, 295147905179352825824, 14063084452067724990975, 708235345355337676357596, 37589973457545958193355563

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = Sum_{i=0..floor((n+2)/(n+1))} ((-1)^i*(n+1)^((n+2) -(n+1)*i)*binomial((n+2) -n*i,i)).

Crossrefs

Subdiagonal 2 of A206455.

Sequence in context: A257367 A072373 A006412 * A386860 A137220 A006236

Adjacent sequences: A206453 A206454 A206455 * A206457 A206458 A206459

Keyword

nonn

Author

R. H. Hardin, Feb 07 2012

Status

approved