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A000649 Number of alkyls C_{n+15} H_{2n+10} (Phenan) with n carbon atoms.
(Formerly M3958 N1633)
1
1, 5, 30, 115, 425, 1396, 4440, 13470, 40000, 116140, 332827, 942435, 2647450, 7386925, 20511620, 56731383, 156451985, 430462915, 1182341890, 3243215495, 8887664047, 24338341165, 66616422775, 182276901760, 498657609720, 1364083988834 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

REFERENCES

G. Polya, Algebraische Berechnung der Anzahl der Isomeren einiger organischer Verbindungen, Zeit. f. Kristall., 93 (1936), 415-443; line 16 of table I.

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).

FORMULA

G.f.: A(x) = (r(x)^10+r(x^2)^5)/2, r(x) = A000598(x).

CROSSREFS

Cf. A000648.

Sequence in context: A062990 A018213 A047661 * A027173 A196452 A054612

Adjacent sequences:  A000646 A000647 A000648 * A000650 A000651 A000652

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 15:27 EST 2012. Contains 205930 sequences.