OFFSET
1,1
COMMENTS
The first term -78 is 6 mod 12 but all subsequent terms are 0,4,8 mod 12. Checked out to n=10000. A117329 is the subsequence formed by taking every 9th term.
The smallest absolute value of the sequence is 0.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(A117345(n)) = 0. - Hugo Pfoertner, Jan 26 2021
EXAMPLE
a(3)=-36 = det([[5,7,11],[13,17,19],[23,29,31]]).
MAPLE
primedet := proc(n) local L; L:=map(ithprime, [$n..n+8]); linalg[det]([L[1..3], L[4..6], L[7..9]]) end;
MATHEMATICA
Table[Det[Partition[Prime[Range[n, n+8]], 3, 3]], {n, 50}] (* Harvey P. Dale, May 16 2019 *)
PROG
(PARI) a(n) = matdet(matrix(3, 3, i, j, prime((n+j-1)+3*(i-1)))); \\ Michel Marcus, Jan 25 2021
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Cino Hilliard and Walter Kehowski, Apr 24 2006
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of Stefan Steinerberger, Jul 14 2007
STATUS
approved