A244412 - OEIS

A244412

Least even k such that sfdf(k-1) > sfdf(k-3) >= A050376(n), where sfdf(n) is the smallest Fermi-Dirac factor of n (A223490), and k-3 is not the lesser of a pair of Fermi-Dirac twin primes (A229064).

%I #7 Jul 07 2014 00:33:06

%S 18,38,38,80,102,212,224,440,440,440,578,728,1250,1460,1742,2012,2282,

%T 3434,3482,4190,4664,4760,4760,6890,7212,7212,7212,8054,10772,12830,

%U 12830,13592,13592,14282,17402,17402,17402,18212,22502,22502,22502,25220,28202

%N Least even k such that sfdf(k-1) > sfdf(k-3) >= A050376(n), where sfdf(n) is the smallest Fermi-Dirac factor of n (A223490), and k-3 is not the lesser of a pair of Fermi-Dirac twin primes (A229064).

%C A Fermi-Dirac analog of A242720.

%e If k>=4 is even such that k-3 is either 1 or in A050376, then k cannot be a solution. Thus, if n=2, then k=4,6,8,10,12,14 are not allowed; for k=16 we have sfdf(16-1) = 3 < sfdf(16-3) = 13; finally, for k=18 we have sfdf(18-1) = 17 > sfdf(18-3) = 3 = A050376(2). Since 15 is not in A229064, then a(2)=18.

%Y Cf. A050376, A223490, A242719, A244343, A242720, A229064.

%K nonn

%O 2,1

%A _Vladimir Shevelev_ and _Peter J. C. Moses_, Jun 27 2014