OFFSET
0,2
LINKS
R. W. Grosse-Kunstleve, Table of n, a(n) for n = 0..1000
R. W. Grosse-Kunstleve, Coordination Sequences and Encyclopedia of Integer Sequences
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 + x) * (1 + x + 2*x^2 + 4*x^3 + 4*x^4 + 3*x^5 + 7*x^6 + 5*x^7 + 7*x^8 + 8*x^9 + 8*x^10 + 8*x^11 + 7*x^12 + 5*x^13 + 7*x^14 + 3*x^15 + 4*x^16 + 4*x^17 + 2*x^18 + x^19 + x^20) / ((1 - x)^3 * (1 + x^2) * (1 - x + x^2 - x^3 + x^4) * (1 - x^2 + x^4) * (1 + x + x^2 + x^3 + x^4)^2). - Colin Barker, Dec 21 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved