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A080187 Primes p such that 11 is the largest of all prime factors of the numbers between p and the next prime (cf. A052248). 1
19, 97, 197, 461, 659, 1319, 1451, 2111, 2309, 2969, 3167, 3299, 4157, 5279, 7127, 9239, 10889, 11549, 15971, 16631, 22637, 25409, 26729, 29567, 30491, 34649, 34847, 55439, 55901, 64151, 87119, 92399, 98009, 110879, 118799, 152459, 164999, 176417 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sequence appears to consist of 19, 97 and the lesser of twin primes q (A001359) such that q+1 is 11-smooth (A051038) but not 7-smooth (A002473, A080195).

LINKS

Table of n, a(n) for n=1..38.

EXAMPLE

97 is a term since 98 = 2*7^2, 99 = 3^2*11, 100 = 2^2*5^2 are the numbers between 97 and the next prime 101; 461 is a term since 462 = 2*3*7*11 is the only number between 461 and the next prime 463.

PROG

(PARI) {forprime(p=2, 180000, q=nextprime(p+1); m=0; j=p+1; while(j<q&&m<=11, f=factor(j); a=f[matsize(f)[1], 1]; if(m<a, m=a); j++); if(m==11, print1(p, ", ")))}

CROSSREFS

Cf. A052248, A001359, A051038, A002473, A080195.

Sequence in context: A173368 A041696 A277977 * A142170 A069593 A086120

Adjacent sequences:  A080184 A080185 A080186 * A080188 A080189 A080190

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Feb 10 2003

STATUS

approved

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Last modified December 17 04:09 EST 2017. Contains 296096 sequences.