|
| |
|
|
A130753
|
|
A folded-back triangular sequence based on symmetry of CnH2*n+2 straight chain alkanes and the number of hydrogen atoms of a given symmetry type: Besides methane at 4 there are only three symmetry types: two CH3's->6: a single CH2->2, two CH2's->4.
|
|
0
| |
|
|
4, 6, 6, 2, 6, 4, 6, 4, 2, 6, 4, 4, 6, 4, 4, 2, 6, 4, 4, 4, 6, 4, 4, 4, 2, 6, 4, 4, 4, 4, 6, 4, 4, 4, 4, 2, 6, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 2, 6, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 2, 6, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4, 2, 6, 4, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4, 4, 2, 6, 4, 4, 4, 4
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
REFERENCES
| http://en.wikipedia.org/wiki/Alkane
|
|
|
FORMULA
| a(n,m) = If[n == m == 1, 4, If[n == 1 && m >1, 6, If[Mod[m, 2] == 1 && n == Floor[m/2] + 1, 2, 4]]]
|
|
|
EXAMPLE
| {4},->Ch4
{6}, ->CH3CH3
{6, 2}, ->CH3CH2CH3
{6, 4}, ->CH3CH2CH2CH3
{6, 4, 2}, ->CH3CH2CH2CH2CH3
{6, 4, 4}, ->CH3CH2CH2CH2CH2CH3
{6, 4, 4, 2}, ->CH3CH2CH2CH2CH2CH2CH3
{6, 4, 4, 4}, ->CH3CH2CH2CH2CH2CH2CH2CH3
|
|
|
MATHEMATICA
| f[n_, m_] = If[n == m ==1, 4, If[n == 1 && m > 1, 6, If[Mod[m, 2] == 1 && n == Floor[m/2] + 1, 2, 4]]]; Table[Table[f[n, m], {n, 1, If[m == 1, 1, If[Mod[m, 2] == 0, Floor[m/2], Floor[m/2] + 1]]}], {m, 1, 20}]; Flatten[%]
|
|
|
CROSSREFS
| Sequence in context: A009465 A199161 A119858 * A021686 A019923 A019800
Adjacent sequences: A130750 A130751 A130752 * A130754 A130755 A130756
|
|
|
KEYWORD
| nonn,tabf
|
|
|
AUTHOR
| Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Jul 13 2007
|
| |
|
|
