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A350679
Irregular triangle read by rows: T(n,k) (n>=0) is the least prime such that T(n,k) + r*i (0 <= i < k) is an arithmetic progression of primes with first difference primorial(n), or 0 if no such prime exists.
0
2, 2, 2, 3, 3, 2, 5, 5, 5, 5, 2, 7, 7, 7, 7, 7, 0, 2, 13, 13, 13, 13, 13, 47, 199, 199, 199, 0, 2, 23, 23, 29, 37, 37, 71, 1019, 3823, 2564251, 60858179, 147692845283, 0, 2, 17, 17, 17, 73, 73, 619, 4657, 4657, 6007, 23143, 23143, 14933623, 834172298383, 894476585908771, 1275290173428391, 0
OFFSET
0,1
EXAMPLE
T(4,7)=47 because the primes 47 + r*i (0 <= i < 7) with r = primorial(4) = 2*3*5*7 = 210 are in arithmetic progression.
Triangle begins
2, 2;
2, 3, 3;
2, 5, 5, 5, 5;
2, 7, 7, 7, 7, 7, 0;
2, 13, 13, 13, 13, 13, 47, 199, 199, 199, 0;
...
MATHEMATICA
Flatten@Table[Join[Table[j=1; While[k=1; While[PrimeQ[Prime@j+ k(r=Times@@Prime@Range@n)], k++]; k<m, j++]; (p=Prime@j), {m, Prime[n+1]-1}], {If[And@@Table[PrimeQ[p+k*r], {k, 0, p-1}], p, 0]}], {n, 0, 4}] (* Giorgos Kalogeropoulos, Jan 12 2022 *)
CROSSREFS
Cf. A002110.
Sequence in context: A194332 A322062 A368460 * A071451 A177868 A178701
KEYWORD
nonn,tabf
AUTHOR
Jean-Marc Rebert, Jan 11 2022
STATUS
approved