|
|
A212876
|
|
Numbers of the form n^2+1 such that 3^(m+3)==9(mod m) where m=n^4-1.
|
|
1
|
|
|
5, 17, 37, 101, 257, 1297, 4357, 14401, 44101, 65537, 828101, 933157, 8122501, 8386817, 12362257, 41990401, 121220101, 157402117, 223502501, 318622501, 378146917, 506700101, 684345601, 702038017
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
The values of n+1 are prime or composite 121, 11011, 108781, 170431...
All composite n+1 == 1(mod 3) ???
|
|
LINKS
|
|
|
EXAMPLE
|
Let n = 10. Then m = n^4-1 = 9999. 3^10002 == 9 (mod 9999), so n^2+1 = 101 is a member of the sequence.
|
|
PROG
|
(PARI) v=List(); for(n=2, 1e6, m=n^4-1; if(Mod(3, m)^(m+3)==9, listput(v, n^2+1))); Vec(v) \\ Charles R Greathouse IV, May 29 2012
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|