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A222205 Number of multi-directed animals with n vertices. 0
1, 4, 20, 110, 636, 3790, 23036, 141946, 883360, 5538098, 34917224, 221125102, 1405276324, 8956020294, 57209977908, 366147270370, 2347081505816, 15065301857194, 96808851937152, 622682497349910, 4008412023724124, 25821543284366686, 166438749582676204 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..23.

A. Bacher, Directed and multi-directed animals on the square lattice with next nearest neighbor edges, arXiv 1301.1365, 2013. See M(t).

FORMULA

See Theorem 9 of Bacher (2013) for a generating function.

CROSSREFS

Sequence in context: A020084 A325956 A026127 * A262394 A271932 A153295

Adjacent sequences:  A222202 A222203 A222204 * A222206 A222207 A222208

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Feb 14 2013

STATUS

approved

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Last modified May 25 02:01 EDT 2020. Contains 334581 sequences. (Running on oeis4.)