Search: id:A067609 Results 1-1 of 1 results found. %I A067609 %S A067609 1,1,3,6,58,861,373141,525901096,92709102076260838, %T A067609 65190291939775823483614581, %U A067609 1416591403847441323962646602694082865630539057192433 %N A067609 Number of stereo alkanes with combinatorial diameter n. %D A067609 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 A067609 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 A067609 Cf. A000602, A000628, A067608, A067610. %Y A067609 Sequence in context: A003098 A045914 A067610 this_sequence A012473 A058161 A012877 %Y A067609 Adjacent sequences: A067606 A067607 A067608 this_sequence A067610 A067611 A067612 %K A067609 nonn %O A067609 1,3 %A A067609 Peter Freyd (pjf(AT)saul.cis.upenn.edu), Feb 02 2002 %E A067609 Edited by Dean Hickerson (dean.hickerson(AT)yahoo.com), Feb 11 2002 Search completed in 0.001 seconds