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A203513 a(n) = A203312(n+1)/A203312(n). 2
3, 49, 2028, 159201, 20342448, 3850078401, 1012487793408, 353293863908769, 157973407966483200, 88087149666575064369, 59928191584204259377152, 48860028872008706126041281 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A093883 for a discussion and guide to related sequences.

LINKS

Table of n, a(n) for n=1..12.

MATHEMATICA

f[j_] := j; z = 12;

v[n_] := Product[Product[f[j]^2 - f[j] f[k] + f[k]^2,

{j, 1, k - 1}], {k, 2, n}]

Table[v[n], {n, 1, z}]          (* A203312 *)

Table[v[n + 1]/v[n], {n, 1, z}] (* A203513 *)

PROG

(Python)

from operator import mul

from functools import reduce

def v(n): return 1 if n==1 else reduce(mul, [reduce(mul, [j**2 - j*k + k**2 for j in range(1, k)]) for k in range(2, n + 1)])

print([v(n + 1)//v(n) for n in range(1, 13)]) # Indranil Ghosh, Jul 26 2017

CROSSREFS

Cf. A093883, A203312.

Sequence in context: A012166 A012068 A012126 * A012040 A012223 A012100

Adjacent sequences:  A203510 A203511 A203512 * A203514 A203515 A203516

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 04 2012

STATUS

approved

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Last modified November 29 01:40 EST 2021. Contains 349416 sequences. (Running on oeis4.)