OFFSET
2,2
EXAMPLE
p = prime(2) = 3, m=1, u = {p + 2^k | 1 <= k <= m} = {5} contains one prime, and no lesser m satisfies this, so A(2,1) = 1.
Square array A(n,k) n > 1 and k >= 1 begins:
1, 2, 3, 4, 6, 7, 12, 15, 16, 18, ...
1, 3, 5, 11, 47, 53, 141, 143, 191, 273, ...
2, 4, 6, 8, 10, 16, 18, 20, 28, 30, ...
1, 3, 5, 7, 9, 15, 23, 29, 31, 55, ...
2, 4, 8, 20, 38, 64, 80, 292, 1132, 4108, ...
1, 13, 21, 33, 81, 129, 285, 297, 769, 3381, ...
2, 6, 30, 162, 654, 714, 1370, 1662, 1722, 2810, ...
3, 7, 39, 79, 359, 451, 1031, 1039, 11311, 30227, ...
1, 3, 5, 7, 9, 13, 15, 17, 23, 27, ...
PROG
(PARI) A(n, k)= {my(nb=0, p=prime(n), m=1); while (nb<k, if (ispseudoprime(p+2^m), nb++); m++); m--}
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Jean-Marc Rebert, Mar 22 2023
STATUS
approved