A038294 Triangle whose (i,j)-th entry is binomial(i,j)*9^(i-j)*4^j.

1, 9, 4, 81, 72, 16, 729, 972, 432, 64, 6561, 11664, 7776, 2304, 256, 59049, 131220, 116640, 51840, 11520, 1024, 531441, 1417176, 1574640, 933120, 311040, 55296, 4096, 4782969, 14880348, 19840464, 14696640, 6531840, 1741824, 258048

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..34.

Mathematica

Table[Binomial[i, j]9^(i-j) 4^j, {i, 0, 10}, {j, 0, i}]//Flatten (* Harvey P. Dale, Sep 04 2019 *)

Crossrefs

Sequence in context: A248309 A317900 A298583 * A214102 A321575 A336610

Adjacent sequences: A038291 A038292 A038293 * A038295 A038296 A038297

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane.

Status

approved