This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A275509 First occurrence of a run of exactly n consecutive integers with an odd number of prime factors. 0

%I

%S 5,2,11,17,41,27,170,279,428,8825,5879,27937,19453,13871,41233,171707,

%T 1100826,1004646,1633357,5460156,11902755,49390927,21627159,38821328,

%U 41983357,619535061,259681234,1250565732,799932281,4168699147,867086432,2487208142,179376463

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

%e 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.

%o (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

%Y Cf. A005408, A066829, A066794.

%K nonn

%O 1,1

%A _G. L. Honaker, Jr._, Jul 30 2016

%E a(9)-a(33) from _Charles R Greathouse IV_, Jul 31 2016

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 6 16:24 EST 2019. Contains 329808 sequences. (Running on oeis4.)