A001886 Hit polynomials. (Formerly M2604 N1031)

3, 6, 44, 180, 1407, 10384, 92896, 911512, 9913152, 117788056, 1519021046, 21123287848, 315034832581, 5015656588706, 84899016219708, 1522394744470356, 28828385427350245, 574839634258405032, 12039133083940334978, 264216869431056251276, 6063573884814663905952

Offset

3,1

References

J. Riordan, The enumeration of permutations with three-ply staircase restrictions, unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963. (See A001883)

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=3..23.

N. J. A. Sloane, Annotated copy of Riordan's Three-Ply Staircase paper (unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963)

Crossrefs

Fourth column of A080018.

Cf. A001883-A001891.

Sequence in context: A202858 A116315 A363475 * A153742 A092198 A133005

Adjacent sequences: A001883 A001884 A001885 * A001887 A001888 A001889

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Vladeta Jovovic and Vladimir Baltic, Jan 20 2003

a(21)-a(23) from Vaclav Kotesovec, Oct 10 2017

Status

approved