OFFSET
1,13
COMMENTS
Conjecture 1. The sequence is unbounded.
Records are 0, 18, 36, 48, 64, 84, 114, 138, 184, 202, 214, 268, 282, 366, 374, 378, 412, 444, 528, ... with indices 1, 13, 19, 43, 144, 145, 167, 560, 635, 981, 982, 2605, 3967, 4582, 7422, 7423, 7424, 7425, 10320, ... .
The places of nonzero terms correspond to places of those terms of A194658 which are in A164288. Moreover, for n>=1, places of nonzero terms of A194659 and A194186(n+1) coincide. This means that these sequences have the same lengths of the series of zeros.
Conjecture 2. The asymptotic density of nonzero terms is 2/(e^2+1).
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16385
PROG
(PARI)
up_to = 65537;
A104272list(n) = { my(L=vector(n), s=0, k=1); for(k=1, prime(3*n)-1, if(isprime(k), s++); if(k%2==0 && isprime(k/2), s--); if(s<n, L[s+1] = k+1)); (L); } \\ From A104272 by Satish Bysany, Mar 02 2017
v104272 = A104272list(65537);
A104272(n) = v104272[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Sep 01 2011
STATUS
approved