A000645 Number of alkyls X^{II} C_n H_{2n+1} Y with n carbon atoms. (Formerly M1209 N0467)

1, 2, 4, 10, 25, 64, 166, 437, 1157, 3087, 8276, 22287, 60230, 163284, 443820, 1209155, 3300890, 9027337, 24727437, 67829684, 186302693, 512301120, 1410237805, 3885803531, 10716571591, 29579231200, 81704634803, 225845362116

Offset

0,2

References

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=0..27.

G. Polya, Algebraische Berechnung der Anzahl der Isomeren einiger organischer Verbindungen, Zeit. f. Kristall., 93 (1936), 415-443; line 11 of Table I.

G. Polya, Algebraische Berechnung der Anzahl der Isomeren einiger organischer Verbindungen, Zeit. f. Kristall., 93 (1936), 415-443; Table 1, line 11. (Annotated scanned copy)

Formula

G.f.: A(x) = A000598(x)/(1-A000642(x)).

Crossrefs

Sequence in context: A307578 A151536 A026269 * A005958 A166516 A230552

Adjacent sequences: A000642 A000643 A000644 * A000646 A000647 A000648

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved