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

1,1

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.

Links

Table of n, a(n) for n=1..55.

Formula

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

Example

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

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

Crossrefs

Cf. A136798, A136799, A136800, A136801.

Sequence in context: A244894 A167611 A151740 * A362866 A084278 A286843

Adjacent sequences: A136799 A136800 A136801 * A136803 A136804 A136805

Keyword

easy,nonn

Author

Enoch Haga, Jan 24 2008

Extensions

Edited by R. J. Mathar, May 27 2009

Status

approved