A369135 a(n) is the lcm of the denominators of the terms in the n-th row of M where M is the inverse of the matrix generated by the triangle A368846.

1, 6, 30, 420, 630, 13860, 180180, 5405400, 4594590, 96996900, 1222160940, 40156716600, 6692786100, 281097016200, 1164544781400, 72201776446800, 2084826294901350, 1895296631728500, 222622144044300, 1823275359722817000, 575032998066426900, 129519337183533297000

Offset

0,2

Comments

See A369134 for comments and formulas.

Links

Table of n, a(n) for n=0..21.

Mathematica

A368846[n_, k_] := If[k == 0, Boole[n == 0], (-1)^(n + k) 2 Binomial[2 k - 1, n] Binomial[2 n + 1, 2 k]];
LCM @@@ Denominator[MapIndexed[Take[#, First[#2]]&, Inverse[PadRight[Table[ A368846[n, k], {n, 0, 25}, {k, 0, n}]]]]] (* Paolo Xausa, Jan 14 2024 *)

Prog

(SageMath)
M = matrix(ZZ, 32, 32, A368846).inverse()
def A369135(n): return lcm(M[n][k].denominator() for k in range(n + 1))
print([A369135(n) for n in range(21)])

Crossrefs

Cf. A369134, A368846.

Sequence in context: A359882 A332041 A201135 * A111876 A119634 A256545

Adjacent sequences: A369132 A369133 A369134 * A369136 A369137 A369138

Keyword

sign

Author

Peter Luschny, Jan 14 2024

Status

approved