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A067609 Number of stereo alkanes with combinatorial diameter n. 3

%I

%S 1,1,3,6,58,861,373141,525901096,92709102076260838,

%T 65190291939775823483614581,

%U 1416591403847441323962646602694082865630539057192433

%N Number of stereo alkanes with combinatorial diameter n.

%D R. Davies and P. J. Freyd, C_{167}H_{336} is The Smallest Alkane with More Realizable Isomers than the Observable Universe has Particles, Journal of Chemical Education, Vol. 66, April 1989, pp. 278-281.

%t f[n_, k_] := Binomial[n+k-1, k]+Binomial[n, k]; rid[0]=1; rid[r_] := rid[r]=1+f[rid[r-1], 3]; rd[r_] := rid[r]-rid[r-1]; td[1]=1; td[r_] := If[EvenQ[r], Binomial[rd[r/2]+1, 2], f[rid[(r-1)/2], 4]-rd[(r-1)/2]f[rid[(r-3)/2], 3]-f[rid[(r-3)/2], 4]]; td/@Range[12]

%Y Cf. A000602, A000628, A067608, A067610.

%K nonn

%O 1,3

%A Peter Freyd (pjf(AT)saul.cis.upenn.edu), Feb 02 2002

%E Edited by _Dean Hickerson_, Feb 11 2002

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Last modified June 14 12:26 EDT 2021. Contains 345025 sequences. (Running on oeis4.)