OFFSET
0,3
COMMENTS
Shifted version of A003703. - R. J. Mathar, May 30 2014
REFERENCES
Edmund Landau, Handbuch der Lehre von der Verteilung der Primzahlen, Chelsea Publishing, NY 1953, pp. 561-562, Section 148.
FORMULA
a(n) = Sum_{k=0..floor((n+1)/2)} (-1)^k*Stirling1(n+1,2*k). - Ammar Khatab, May 23 2021
EXAMPLE
Table of n, Product_{k=0..n} (i-k):
0, i
1, -1 - i
2, 3 + i
3, -10
4, 40 - 10*i
5, -190 + 90*i
6, 1050 - 730*i
7, -6620 + 6160*i
8, 46800 - 55900*i
9, -365300 + 549900*i
10, 3103100 - 5864300*i
11, -28269800 + 67610400*i
12, 271627200 - 839594600*i
MATHEMATICA
Table[Re[(I - n)*Pochhammer[1 + I - n, n]], {n, 0, 25}] (* Vaclav Kotesovec, May 23 2021 *)
PROG
(PARI) a(n) = real(prod(k=0, n, I-k)); \\ Michel Marcus, Jan 03 2021
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, May 29 2014
STATUS
approved