OFFSET
1,2
LINKS
Eric Weisstein's MathWorld, Incomplete Gamma Function
FORMULA
a(n) = |Gamma(n, i)|^2 = Gamma(n, i)*Gamma(n, -i), where i = sqrt(-1).
Recurrence: n*(n-1)*(a(n-1) - (n-2)^2*a(n-2) + 1) + a(n+1) = n^2*a(n) + 1.
a(n) ~ (n-1)!^2. - Vaclav Kotesovec, Oct 15 2016
MATHEMATICA
RecurrenceTable[{n (n - 1) (a[n - 1] - (n - 2)^2 a[n - 2] + 1) + a[n + 1] == n^2 a[n] + 1, a[1] == 1, a[2] == 2, a[3] == 5}, a[n], {n, 1, 20}] (* or *)
Round[Abs[Gamma[Range[20], I]]^2]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Reshetnikov, Oct 14 2016
STATUS
approved