OFFSET
1,1
COMMENTS
All terms == 8 (mod 10).
Are there negative terms? The first 10^7 are positive.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
The first primes ending in 1,3,7,9 are 11,3,7,19, so a(1) = 11*19 - 3*7 = 188.
The second primes ending in 1,3,7,9 are 31,13,17,29, so a(2) = 31*29 - 13*17 = 678.
The third primes ending in 1,3,7,9 are 41,23,37,59, so a(3) = 41*59 - 23*37 = 1568.
MAPLE
R:= NULL:
L:= [-9, -7, -3, -1]:
for k from 1 to 100 do
for i from 1 to 4 do
for x from L[i]+10 by 10 do until isprime(x);
L[i]:= x;
od;
R:= R, L[1]*L[4]-L[2]*L[3];
od:
R;
CROSSREFS
KEYWORD
AUTHOR
J. M. Bergot and Robert Israel, Jan 27 2021
STATUS
approved