OFFSET
0,2
LINKS
R. W. Grosse-Kunstleve, Table of n, a(n) for n = 0..1000
Sean A. Irvine, Generating Functions for Coordination Sequences of Zeolites, after Grosse-Kunstleve, Brunner, and Sloane
International Zeolite Association, Database of Zeolite Structures
FORMULA
G.f.: (1 + 4*x + 10*x^2 + 20*x^3 + 31*x^4 + 46*x^5 + 52*x^6 + 48*x^7 + 45*x^8 + 24*x^9 + 6*x^10 + 4*x^11 - x^12 - 2*x^13) / (1 - x^4)^3.
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Mar 18 2018
STATUS
approved