

A007180


Expansion of critical exponent for walks on tetrahedral lattice.
(Formerly M2674)


0



3, 7, 19, 53, 147, 401, 1123, 3137, 8793, 24599, 69287, 194967, 550361, 1552645, 4393021, 12425121, 35213027, 99771855, 283162701, 803538483, 2283184527, 6486977223, 18450767769, 52477038631, 149387309235, 425257329235, 1211493474199
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OFFSET

1,1


COMMENTS

Using coordinates (x,y,z,t) such that x+y+z+t = 0 or 1, then the four neighbors of (x,y,z,t) are found by changing one coordinate by + 1 (such that the sum of coordinates remains 0 or 1). This sequence gives the number of selfavoiding walks of length n starting from (0,0,0,0) such that t <= z.  Sean A. Irvine, Nov 10 2017


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=1..27.
T. Ishinabe and S. G. Whittington, Surface critical exponents for selfavoiding walks on the tetrahedral lattice, J. Phys. A 14 (1981), 439446.


CROSSREFS

Sequence in context: A115254 A222324 A090378 * A059506 A007575 A026299
Adjacent sequences: A007177 A007178 A007179 * A007181 A007182 A007183


KEYWORD

nonn,walk


AUTHOR

Simon Plouffe


EXTENSIONS

a(20)a(27) from Sean A. Irvine, Nov 10 2017


STATUS

approved



