A369097 Least starting prime of exactly n consecutive primes p_i (i = 1..n) such that bigomega(p_i + 1) = 1 + i.

3, 5, 541, 997, 328753, 5385217, 1287133, 9483302497, 107887226353

Offset: 1

Author

Jean-Marc Rebert, Jun 07 2024

Keywords

• nonn
• more

Examples

			a(1) = 3, because bigomega(3+1) = 2 and no lesser number has this property.
a(2) = 5, because bigomega(5+1) = 2 and bigomega(7+1) = 3, and no lesser number has this property.
a(3) = 541, because bigomega(541+1) = 2, bigomega(547+1) = 3, bigomega(557+1) = 4 and no lesser number has this property.
		

Crossrefs

Cf. A001222, A072875.

Programs

PARI

isok(p, n) = if (bigomega(p+1) != 2, return(0)); for (i=1, n-1, p = nextprime(p+1); if (bigomega(p+1) != i+2, return(0))); if (bigomega(nextprime(p+1)+1) == n+2, return(0)); return(1);
a(n) = my(p=2); while (!isok(p, n), p = nextprime(p+1)); p; \\ Michel Marcus, Jun 07 2024