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A074811 Least k such that prime(k) >= k*tau(k*n) where tau = A000005. 0
1, 1, 1, 181, 1, 1061, 1, 1061, 181, 1061, 1, 40123, 1, 1061, 1061, 6473, 1, 40123, 1, 40123, 1061, 1061, 1, 1617211, 181, 1061, 1061, 40123, 1, 1617211, 1, 40123, 1061, 1061, 1061, 10553429, 1, 1061, 1061, 1617211, 1, 1617211, 1, 40123, 40123, 1061, 1, 69709687 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Listed terms are = 1 or are primes.

a(n) = 1 iff n = 1 or n is prime. - Bernard Schott, Apr 10 2020

LINKS

Table of n, a(n) for n=1..48.

PROG

(PARI) a(n)=if(n<0, 0, my(s=1); while(prime(s)<s*numdiv(s*n), s++); s)

(PARI) a(n)= my(k=1, p=2); while(p<k*numdiv(k*n), k++; p=nextprime(p+1)); k; \\ Michel Marcus, Apr 05 2020

CROSSREFS

Cf. A000005.

Sequence in context: A177327 A236235 A225349 * A036200 A253432 A218977

Adjacent sequences:  A074808 A074809 A074810 * A074812 A074813 A074814

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Sep 08 2002

EXTENSIONS

More terms from Jinyuan Wang, Apr 05 2020

Name corrected by Bernard Schott, Apr 10 2020

STATUS

approved

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Last modified December 5 09:47 EST 2020. Contains 338945 sequences. (Running on oeis4.)