A123312 a(n) = A123311(n)/(n+1), where A123311 forms the central terms of triangle A123305.

1, 1, 6, 84, 2010, 70596, 3331006, 199417056, 14559631506, 1259526351000, 126308710634414, 14434568970310656, 1854260500658184762, 264771440776810595320, 41635233706865669566110

Offset: 0

Author

Paul D. Hanna, Sep 25 2006

Keywords

• nonn
• more

Comments

Triangle T=A123305 is defined by: (column k of T) = (k+1)*(column k of T^2) shifted to have an initial '1'; thus a(n) = A123311(n)/(n+1) is an integer for n>=0.

Crossrefs

Cf. A123305; A123306, A123307, A123308, A123309, A123310, A123311.