login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108669 Triangle read by rows: T(n,k)=11kn+14(n+k)+20 (0<=k<=n). 0
20, 34, 59, 48, 84, 120, 62, 109, 156, 203, 76, 134, 192, 250, 308, 90, 159, 228, 297, 366, 435, 104, 184, 264, 344, 424, 504, 584, 118, 209, 300, 391, 482, 573, 664, 755, 132, 234, 336, 438, 540, 642, 744, 846, 948, 146, 259, 372, 485, 598, 711, 824, 937 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

Kekule numbers for certain benzenoids.

REFERENCES

S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p.102).

FORMULA

G:=(20-6z-tz-16tz^2+3t^2*z^2)/[(1-z)^2*(1-tz)^3]

EXAMPLE

Triangle begins:

20;

34,59;

48,84,120;

62,109,156,203;

MAPLE

T:=proc(n, k) if k<=n then 11*k*n+14*(n+k)+20 else 0 fi end: for n from 0 to 10 do seq(T(n, k), k=0..n) od; # yields sequence in triangular form

CROSSREFS

Sequence in context: A067468 A127906 A108667 * A039343 A043166 A043946

Adjacent sequences:  A108666 A108667 A108668 * A108670 A108671 A108672

KEYWORD

nonn,tabl

AUTHOR

Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 14 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 14:07 EST 2012. Contains 205623 sequences.