login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A011827
f-vectors for simplicial complexes of dimension at most 2 on at most n-1 vertices.
2
2, 3, 5, 10, 25, 70, 190, 471, 1060, 2189, 4203, 7592, 13027, 21400, 33868, 51901, 77334, 112423, 159905, 223062, 305789, 412666, 549034, 721075, 935896, 1201617, 1527463, 1923860, 2402535, 2976620, 3660760, 4471225, 5426026
OFFSET
1,1
FORMULA
a(n+1)= (2*n^6 -6*n^5 +5*n^4 +60*n^3 -7*n^2 +306*n +720)/360 fits terms up to 5426026. [Frank Ellermann]
Empirical G.f.: -x*(x^6-7*x^5+25*x^4-32*x^3+26*x^2-11*x+2)/(x-1)^7. [Colin Barker, Sep 19 2012]
CROSSREFS
Cf. A011826.
Sequence in context: A001200 A050837 A107578 * A260304 A259438 A135961
KEYWORD
nonn
AUTHOR
Svante Linusson (linusson(AT)math.kth.se)
STATUS
approved