A038335 Triangle whose (i,j)-th entry is binomial(i,j)*12^(i-j)*9^j.

1, 12, 9, 144, 216, 81, 1728, 3888, 2916, 729, 20736, 62208, 69984, 34992, 6561, 248832, 933120, 1399680, 1049760, 393660, 59049, 2985984, 13436928, 25194240, 25194240, 14171760, 4251528, 531441, 35831808, 188116992, 423263232

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..30.

Example

       1
      12        9
     144      216       81
    1728     3888     2916      729
   20736    62208    69984    34992     6561
  248832   933120  1399680  1049760   393660    59049
 2985984 13436928 25194240 25194240 14171760  4251528   531441

Maple

A038335 := proc(i, j)
    binomial(i, j)*12^(i-j)*9^j ;
end proc: # R. J. Mathar, Nov 22 2022

Mathematica

Flatten[Table[Binomial[i, j]12^(i-j) 9^j, {i, 0, 10}, {j, 0, i}]] (* Harvey P. Dale, Oct 17 2013 *)

Crossrefs

Cf. A009965 (row sums), A001021 (column 0), A001019 (diagonal)

Sequence in context: A327470 A068614 A163920 * A359737 A216856 A040023

Adjacent sequences: A038332 A038333 A038334 * A038336 A038337 A038338

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane.

Status

approved