A275509 First occurrence of a run of exactly n consecutive integers with an odd number of prime factors.

5, 2, 11, 17, 41, 27, 170, 279, 428, 8825, 5879, 27937, 19453, 13871, 41233, 171707, 1100826, 1004646, 1633357, 5460156, 11902755, 49390927, 21627159, 38821328, 41983357, 619535061, 259681234, 1250565732, 799932281, 4168699147, 867086432, 2487208142, 179376463

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Example

a(3) = 11 because 11 begins the first occurrence of a run of exactly 3 consecutive integers with an odd number of prime factors, i.e., 11, 12 = 2 * 2 * 3, 13.

Prog

(PARI) v=vector(100); last=0; for(n=1, 1e10, if(bigomega(n)%2==0, t=n-last-1; if(t && v[t]==0, v[t]=n-t; print(t" "n-t)); last=n)) \\ Charles R Greathouse IV, Jul 31 2016

Crossrefs

Cf. A005408, A066829, A066794.

Sequence in context: A302773 A249369 A065268 * A286142 A286143 A130298

Adjacent sequences: A275506 A275507 A275508 * A275510 A275511 A275512

Keyword

nonn

Author

G. L. Honaker, Jr., Jul 30 2016

Extensions

a(9)-a(33) from Charles R Greathouse IV, Jul 31 2016

Status

approved