25781

Appears in sequences

• a(n) = a(n-1) + Sum_{k=0..n-4} a(k)*a(n-4-k), a(0) = 1. Generalized Catalan Numbers.at n=20A023426
• Number of 7-length words w over n-ary alphabet such that for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z.at n=6A213286
• Number of n-length words w over 6-ary alphabet such that for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z.at n=7A213294
• Irregular array read by rows. a(n) is the largest element in the primitive Collatz-like 3x-k cycle associated with A226623(n).at n=12A226624
• Erroneous version of A271811 (but for odd primes only).at n=21A271664
• a(n) = Bell(n-1)*Motzkin(n).at n=6A290445
• E.g.f.: Product_{k>=1} 1 / (1 - x^k)^(exp(-x)/k).at n=8A346546