A085809 Indices of semiprimes where largest gap occurs. Or, positions of records in A065516.

1, 2, 4, 6, 10, 34, 186, 422, 760, 1765, 4112, 4585, 8112, 8650, 8861, 75150, 223993, 327048, 712605, 1135940, 23958638, 42367759, 47848742, 54626559, 121984495, 157877985, 413509327, 798321315, 983679985, 1277946119, 2403158480

Offset: 1

Author

Jason Earls, Jul 24 2003

Keywords

• nonn

Comments

A215231(n) = A065516(a(n)). - Reinhard Zumkeller, Mar 23 2014

Crossrefs

Cf. A239674.

Programs

Haskell

a085809 n = a085809_list !! (n-1)
-- See A215231 for definition of a085809_list.
-- Reinhard Zumkeller, Mar 23 2014

PARI

{sgr(m)=local(a,b,rec,c); c=0; a=0; b=4; rec=0; for(n=5,m,if(bigomega(n)==2,c++; a=n; if(a-b>rec,rec=a-b; print1(c","); b=a,b=a; )))}

Extensions

a(19)-a(26) from Donovan Johnson, Jan 28 2009

a(27)-a(31) from Donovan Johnson, Apr 14 2010