A038273 Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j)*7^j.
1, 7, 7, 49, 98, 49, 343, 1029, 1029, 343, 2401, 9604, 14406, 9604, 2401, 16807, 84035, 168070, 168070, 84035, 16807, 117649, 705894, 1764735, 2352980, 1764735, 705894, 117649, 823543, 5764801, 17294403, 28824005, 28824005
Offset: 0
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.