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A080185 Primes p such that 5 is the largest of all prime factors of the numbers between p and the next prime (cf. A052248). 1
7, 29, 59, 149, 179, 239, 269, 599, 809, 1619, 2999, 4049, 4799, 8999, 9719, 15359, 21599, 23039, 33749, 138239, 179999, 281249, 345599, 737279, 3455999, 6143999, 6560999, 10124999, 13668749, 15551999, 17495999, 20995199, 22118399, 23999999 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sequence consists of 7 and the lesser of twin primes q (A001359) such that q+1 is 5-smooth (A051037) but not 3-smooth (A003586, A080193).

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

7 is a term since 8 = 2^3, 9 = 3^3, 10 = 2*5 are the numbers between 7 and the next prime 11; 149 is a term since 150 = 2*3*5^2 is the only number between 149 and the next prime 151.

PROG

(PARI) {forprime(p=2, 24000000, q=nextprime(p+1); m=0; j=p+1; while(j<q&&m<=5, f=factor(j); a=f[matsize(f)[1], 1]; if(m<a, m=a); j++); if(m==5, print1(p, ", ")))}

CROSSREFS

Cf. A052248, A001359, A051037, A003586, A080193.

Sequence in context: A084201 A031380 A005698 * A219835 A041621 A022272

Adjacent sequences:  A080182 A080183 A080184 * A080186 A080187 A080188

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Feb 10 2003

STATUS

approved

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Last modified July 21 19:13 EDT 2019. Contains 325199 sequences. (Running on oeis4.)