A038270 Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j)*4^j.

1, 7, 4, 49, 56, 16, 343, 588, 336, 64, 2401, 5488, 4704, 1792, 256, 16807, 48020, 54880, 31360, 8960, 1024, 117649, 403368, 576240, 439040, 188160, 43008, 4096, 823543, 3294172, 5647152, 5378240, 3073280, 1053696, 200704, 16384

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..35.

Mathematica

Table[Binomial[n, k]7^(n-k) 4^k, {n, 0, 10}, {k, 0, n}]//Flatten (* Harvey P. Dale, May 26 2020 *)

Crossrefs

Sequence in context: A270937 A270320 A270332 * A241359 A239602 A374295

Adjacent sequences: A038267 A038268 A038269 * A038271 A038272 A038273

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane.

Status

approved