A136802 The composite with the largest prime factor in the n-th prime gap larger than 2.

10, 14, 22, 26, 34, 38, 46, 51, 58, 62, 69, 74, 82, 86, 94, 99, 106, 111, 122, 129, 134, 146, 155, 158, 166, 172, 178, 183, 194, 206, 218, 226, 232, 237, 249, 254, 262, 267, 274, 278, 291, 302, 309, 314, 326, 334, 346, 351, 358, 362, 371, 376, 382, 386, 394

Offset: 1

Author

Enoch Haga, Jan 24 2008

Keywords

• easy
• nonn

Comments

Pick the number in the interval [A136798(n),A136799(n)] with the largest prime factor.

The sequence is obtained from A114331 by removing terms in prime gaps of size 2.

Examples

			a(1)=10 because at N=10 the largest prime factor is 5.
		

Crossrefs

Cf. A136798, A136799, A136800, A136801.

Programs

Maple

A006530 := proc(n) max( op(numtheory[factorset](n))) ; end:
A136798 := proc(n) local a; if n = 1 then 8; else a := nextprime( procname(n-1))+1 ; while nextprime(a)-a <=2 do a := nextprime(a)+1 ; od; RETURN(a) ; fi; end:
A136802 := proc(n) local c,lpf,a; c := A136798(n) ; lpf := A006530(c) ; a := c; while not isprime(c+1) do c := c+1 ; if A006530(c) > lpf then a := c ; lpf := A006530(c) ; fi; od: a ; end:
seq(A136802(n),n=1..80) ; # R. J. Mathar, May 27 2009

Formula

A006530(a(n)) = A136801(n).

Extensions

Edited by R. J. Mathar, May 27 2009