A038215 Triangle whose (i,j)-th entry is binomial(i,j)*2^(i-j)*9^j.

1, 2, 9, 4, 36, 81, 8, 108, 486, 729, 16, 288, 1944, 5832, 6561, 32, 720, 6480, 29160, 65610, 59049, 64, 1728, 19440, 116640, 393660, 708588, 531441, 128, 4032, 54432, 408240, 1837080, 4960116, 7440174, 4782969, 256, 9216, 145152

Offset

0,2

References

B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.

Links

Table of n, a(n) for n=0..38.

Mathematica

Table[Binomial[x, y]2^(x-y) 9^y, {x, 0, 10}, {y, 0, x}]//Flatten (* Harvey P. Dale, Jun 17 2017 *)

Crossrefs

Sequence in context: A002508 A353242 A249596 * A264110 A119019 A268204

Adjacent sequences: A038212 A038213 A038214 * A038216 A038217 A038218

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane.

Status

approved