A055342 Number of mobiles (circular rooted trees) with n nodes and 4 leaves.

1, 4, 16, 46, 118, 260, 527, 985, 1741, 2918, 4701, 7299, 11004, 16142, 23148, 32502, 44823, 60786, 81238, 107098, 139492, 179632, 228979, 289097, 361841, 449188, 553453, 677093, 822954, 994044, 1193814, 1425902, 1694445, 2003790

Offset

5,2

Links

Table of n, a(n) for n=5..38.

Index entries for sequences related to mobiles

Formula

Conjecture: G.f. x^5*( -1-x-5*x^2-6*x^3-9*x^4-5*x^5-2*x^6-2*x^7+x^9 ) / ( (x^2+1)*(1+x+x^2) *(1+x)^3 *(x-1)^7 ). - R. J. Mathar, Sep 18 2011

Crossrefs

Column 4 of A055340.

Sequence in context: A374320 A374262 A007315 * A213292 A174836 A244252

Adjacent sequences: A055339 A055340 A055341 * A055343 A055344 A055345

Keyword

nonn

Author

Christian G. Bower, May 14 2000

Status

approved