A351697 32*a(n) is the denominator of the squared circumradius of a cyclic quadrilateral with sides n, n+1, n+2, n+3.

3, 15, 5, 105, 210, 42, 630, 990, 165, 2145, 3003, 455, 5460, 7140, 1020, 11628, 14535, 1995, 21945, 26565, 3542, 37950, 44850, 5850, 61425, 71253, 9135, 94395, 107880, 13640, 139128, 157080, 19635, 198135, 221445, 27417, 274170, 303810, 37310, 370230, 407253, 49665

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Formula

a(n) = denominator(b(n)), where b(n) = (8*(2*n^6 + 18*n^5 + 65*n^4 + 120*n^3 + 117*n^2 + 54*n + 9))/(n^4 + 6*n^3 + 11*n^2 + 6*n).

Example

(1/32)*{385/3, 3289/15, 1729/5, 53041/105, 146329/210, 38665/42, ...}

Crossrefs

A351696 gives the corresponding numerators.

Cf. A000332, A052762, A345665, A351698.

Sequence in context: A088558 A212203 A286783 * A012881 A248031 A066832

Adjacent sequences: A351694 A351695 A351696 * A351698 A351699 A351700

Keyword

nonn,frac

Author

Hugo Pfoertner, Feb 26 2022

Status

approved