A000622 - OEIS

A000622

Number of monosubstituted alkanes C(n)H(2n+1)-X of the form shown in the Comments lines that are stereoisomers.
(Formerly M1272 N0490)

0, 0, 0, 2, 4, 14, 34, 98, 270, 768, 2192, 6360, 18576, 54780, 162658, 486154, 1461174, 4413988, 13393816, 40807290, 124783604, 382842018, 1178140170, 3635626680, 11247841040, 34880346840, 108402132234, 337576497920, 1053229357732, 3291813720292, 10305275270364

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

COMMENTS

R-CH-X (secondary)

.....|

.....R'

Let the entries in the nine columns of Blair and Henze's Table I (JACS 54 (1932), p. 1098) be denoted by Ps(n), Pn(n), Ss(n), Sn(n), Ts(n), Tn(n), As(n), An(n), T(n) respectively (here P = Primary, S = Secondary, T = Tertiary, s = stereoisomers, n = non-stereoisomers and the last column T(n) gives total).

Then Ps (and As) = A000620, Pn (and An, Sn) = A000621, Ss = this sequence, Ts = A000623, Tn = A000624, T = A000625. Recurrences generating these sequences are given in the Maple program in A000620.

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

Vaclav Kotesovec, Table of n, a(n) for n = 1..1930

C. M. Blair and H. R. Henze, The number of stereoisomeric and non-stereoisomeric mono-substitution products of the paraffins, J. Amer. Chem. Soc., 54 (3) (1932), 1098-1106.

C. M. Blair and H. R. Henze, The number of stereoisomeric and non-stereoisomeric mono-substitution products of the paraffins, J. Amer. Chem. Soc., 54 (3) (1932), 1098-1105. (Annotated scanned copy)

FORMULA

a(n) ~ c * b^n / n^(3/2), where b = 3.287112055584474991259... (see A239803), c = 0.171310881484463744523... (see A239807). - Vaclav Kotesovec, Mar 27 2014

CROSSREFS

Cf. A000620-A000625, A239803, A239807.

Sequence in context: A148264 A148265 A148266 * A088028 A327459 A336108

Adjacent sequences: A000619 A000620 A000621 * A000623 A000624 A000625

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

EXTENSIONS

Additional comments from Bruce Corrigan, Nov 04 2002

STATUS

approved