A218289 Denominator of the sixth increasing diagonal of the autosequence of the second kind from (-1)^n/(n+1).

6, 12, 12, 12, 210, 168, 504, 72, 198, 660, 1716, 1092, 546, 336, 4080, 2448, 5814, 684, 1596, 4620, 10626, 6072, 2760, 1560, 17550, 9828, 21924, 2436, 5394, 14880, 32736, 17952, 7854, 4284, 46620, 25308, 54834

Offset: 0

Author

Paul Curtz, Oct 25 2012

Keywords

• nonn

Comments

See A194767. a(n) is a multiple of 6. The terms 6, 210, 504, 1716, 4080, 5814, ... have the form k*(k+1)*(k+2), for k = 1, 5, 7, 11, 15, 17, 21, 25, ... .

Links

• OEIS Wiki, Autosequence

Crossrefs

Cf. A208950(n+2).

Formula

a(n) = A007531(n+3)/s(n) = (n+1)*(n+2)*(n+3)/s(n) where s(n) repeats 1, 2, 5, 10, 1, 2, 1, 10, 5, 2.

a(n) = (n+1)*(n+2)*(n+3)*a(n-10)/((n-7)*(n-8)*(n-9)) for n>9 (empirical). - Jean-François Alcover, Nov 29 2016