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A037209 Primes n such that nextprime(n) - n = ( number of divisors of (nextprime(n)+n)/2 )-1. 0

%I #8 Jan 08 2019 09:12:41

%S 3,61,79,317,4730603,9150613,14791703,27154511,59259191,203404631,

%T 234273623,237683879,263802551,314778551,477772151,500998679,

%U 507736049,628103831,803042231,1047040151,1222341431,1516790903,1826793071,2037439031,2070067991,2310340343

%N Primes n such that nextprime(n) - n = ( number of divisors of (nextprime(n)+n)/2 )-1.

%o (PARI) p1=3; for(m=2, 112664172, p2=nextprime(p1+1); if(p2-p1==numdiv((p2+p1)/2)-1, print1(p1 ", ")); p1=p2) /* _Donovan Johnson_, Sep 10 2012 */

%K nonn

%O 1,1

%A _Naohiro Nomoto_

%E Next term if it exists is > 2*10^6. - _Michel ten Voorde_ Apr 13 2001

%E Offset corrected and a(5)-a(26) from _Donovan Johnson_, Sep 10 2012

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Last modified March 28 17:25 EDT 2024. Contains 371254 sequences. (Running on oeis4.)