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 + 6*x^2 + 12*x^3 + 16*x^4 + 24*x^5 + 30*x^6 + 32*x^7 + 35*x^8 + 32*x^9 + 34*x^10 + 24*x^11 + 16*x^12 + 12*x^13 + 6*x^14 + 4*x^15) / (1 - x^4) / (1 - x^6)^2.
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Mar 19 2018
STATUS
approved