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).

18, 38, 38, 80, 102, 212, 224, 440, 440, 440, 578, 728, 1250, 1460, 1742, 2012, 2282, 3434, 3482, 4190, 4664, 4760, 4760, 6890, 7212, 7212, 7212, 8054, 10772, 12830, 12830, 13592, 13592, 14282, 17402, 17402, 17402, 18212, 22502, 22502, 22502, 25220, 28202

Offset

2,1

Comments

A Fermi-Dirac analog of A242720.

Links

Table of n, a(n) for n=2..44.

Example

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.

Crossrefs

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

Sequence in context: A041642 A041644 A041646 * A114698 A119127 A190739

Adjacent sequences: A244409 A244410 A244411 * A244413 A244414 A244415

Keyword

nonn

Author

Vladimir Shevelev and Peter J. C. Moses, Jun 27 2014

Status

approved