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A126886
Triangle read by rows, arising in enumeration of 4-trees by diameter.
0
1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 5, 6, 8, 7, 7, 5, 5, 3, 2, 1, 1, 1, 2, 7, 12, 23, 30, 42, 47, 55, 53, 53, 45, 40, 29, 23
OFFSET
0,8
COMMENTS
See reference for precise definition.
LINKS
A. T. Balaban, J. W. Kennedy and L. V. Quintas, The number of alkanes having n carbons and a longest chain of length d, J. Chem. Education, 65 (1988), 304-313.
EXAMPLE
Triangle begins:
1
1
1 1 1
1 1 2 1 1
1 2 5 6 8 7 7 5 5 3 2 1 1
1 2 7 12 23 30 42 47 55 53 53 45 40 29 23 ...
CROSSREFS
Cf. A000602 (diagonal sums when rows are displaced by the appropriate amounts), A036437.
Sequence in context: A308035 A336479 A221131 * A179272 A264753 A165680
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Aug 04 2007
STATUS
approved