A002976 Number of certain self-avoiding walks with n steps on square lattice (see reference for precise definition). (Formerly M0034)

0, 1, 0, 2, 0, 5, 9, 21, 42, 76, 174, 396, 888, 2023, 4345, 9921, 22566, 52436, 121330, 280300, 652577, 1526588, 3593881, 8499891, 20122183, 47851464, 114106883, 272918157, 655503331, 1575651737, 3804038107, 9190693494, 22282629123, 54116568153, 131689795621, 321266555821, 784607412699

Offset

4,4

References

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=4..40.

W. A. Beyer, Letter to N. J. A. Sloane, 1980

W. A. Beyer and M. B. Wells, Lower bound for the connective constant of a self-avoiding walk on a square lattice, J. Combin. Theory, A 13 (1972), 176-182.

Bert Dobbelaere, C++ program

Formula

a(n) = A006142(n) + 2*A006143(n) + A006144(n). - R. J. Mathar, Oct 22 2007

Crossrefs

Cf. A001411, A037245.

Sequence in context: A227569 A344786 A011014 * A358305 A292590 A080901

Adjacent sequences: A002973 A002974 A002975 * A002977 A002978 A002979

Keyword

nonn,walk,changed

Author

N. J. A. Sloane

Extensions

a(21)-a(40) from Bert Dobbelaere, May 08 2026

Status

approved