The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A067665 The start of a record-setting run of consecutive integers i with distinct A001222(i). 4
 1, 6, 15, 60, 726, 6318, 189375, 755968, 683441871, 33714015615 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The list of indices of record terms in A068796; n is in the sequence if A068796(n) is larger than A068796(m) when n is larger than m. For the known terms, f(a(n)) = n+1. Is that true for all n? In other words, is the monotonic subsequence of A068796 identical to A020725? a(11) > 10^13. - Giovanni Resta, Jan 08 2014 LINKS J.-M. De Koninck, J. B. Friedlander, and F. Luca, On strings of consecutive integers with a distinct number of prime factors, Proc. Amer. Math. Soc., 137 (2009), 1585-1592. EXAMPLE The values of f(n) for n=1 to 15 are 2,1,2,2,2,3,3,2,1,3,2,3,2,1,4. Records occur at f(1)=2, f(6)=3 and f(15)=4. MATHEMATICA bigomega[n_] := Plus@@Last/@FactorInteger[n]; f[n_] := For[k=1; s={bigomega[n]}, True, k++, If[MemberQ[s, z=bigomega[n+k]], Return[k], AppendTo[s, z]]]; For[n=1; max=0, True, n++, If[f[n]>max, Print[n, " ", max=f[n]]]] PROG (PARI) a(n, lim=1e12, startAt=1)={   forstep(i=startAt-1, lim, 10^6-n,     my(v=vectorsmall(min(10^6, lim\1-i), j, bigomega(j+i)));     for(j=n, #v, if(#vecsort(v[j-n+1..j], , 8)==n, return(j+i-n+1)))   ) }; \\ Charles R Greathouse IV, Jul 03 2013 CROSSREFS Cf. A001222, A067650, A068069, A068796, A068797. Sequence in context: A271002 A271018 A145638 * A012595 A012294 A219811 Adjacent sequences:  A067662 A067663 A067664 * A067666 A067667 A067668 KEYWORD more,nonn AUTHOR G. L. Honaker, Jr., Feb 03 2002 EXTENSIONS More terms from Shyam Sunder Gupta, Feb 08 2002 Edited by Robert G. Wilson v, Feb 20 2002 Edited by Dean Hickerson, Mar 05 2002 a(10) from Donovan Johnson, Oct 15 2008 STATUS approved

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 June 2 11:35 EDT 2020. Contains 334771 sequences. (Running on oeis4.)