A038251 Triangle whose (i,j)-th entry is binomial(i,j)*5^(i-j)*9^j.

1, 5, 9, 25, 90, 81, 125, 675, 1215, 729, 625, 4500, 12150, 14580, 6561, 3125, 28125, 101250, 182250, 164025, 59049, 15625, 168750, 759375, 1822500, 2460375, 1771470, 531441, 78125, 984375, 5315625, 15946875, 28704375, 31000725

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..33.

Mathematica

Table[Binomial[i, j]5^(i-j) 9^j, {i, 0, 10}, {j, 0, i}]//Flatten (* Harvey P. Dale, May 18 2023 *)

Crossrefs

Sequence in context: A062812 A032499 A112084 * A034498 A219499 A048884

Adjacent sequences: A038248 A038249 A038250 * A038252 A038253 A038254

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane.

Status

approved