login
A373511
Expansion of 1/(1 - x/(1 - 49*x^7)^(1/7)).
2
1, 1, 1, 1, 1, 1, 1, 1, 8, 15, 22, 29, 36, 43, 50, 253, 505, 806, 1156, 1555, 2003, 2500, 9906, 20105, 33440, 50254, 70890, 95691, 125000, 423270, 861190, 1467915, 2275001, 3316405, 4628485, 6250000, 18944976, 38420768, 66538494, 105430585, 157517592, 225524993, 312500000
OFFSET
0,9
FORMULA
a(7*n) = 50^(n-1) for n > 0.
a(n) = Sum_{k=0..floor(n/7)} 49^k * binomial(n/7-1,k).
a(n) == 1 (mod 7).
PROG
(PARI) a(n) = sum(k=0, n\7, 49^k*binomial(n/7-1, k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jun 07 2024
STATUS
approved