OFFSET
1,3
COMMENTS
Assuming Dickson's conjecture, T(n,k) always exists.
T(n,1) is odd.
T(n,k) is even for any k > 1.
A229980(n) = T(n+1, n) for any n > 0.
LINKS
Rémy Sigrist, Rows n=1..100 of triangle, flattened
OEIS Wiki, Dickson's conjecture
EXAMPLE
prime(7) + m*prime(11) is prime for m = 2, 12, 24, 26, 30, ...
m*prime(7) + prime(11) is prime for m = 8, 14, 18, 24, 30, ...
Hence, T(11,7) = 24.
The triangle T(n,k) begins:
n\k 1 2 3 4 5 6 7 8 9
1:
2: 1
3: 1 2
4: 3 2 2
5: 1 4 6 6
6: 3 2 2 4 6
7: 1 2 4 2 4 2
8: 5 4 2 4 8 4 14
9: 3 10 4 2 4 6 12 6
10: 1 10 6 6 4 14 6 8 6
PROG
(PARI) t(n, k) = my (pn=prime(n), pk=prime(k), i=1); while (!isprime(pn+i*pk) || !isprime(i*pn+pk), i++); return (i)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Rémy Sigrist, May 14 2017
STATUS
approved