A071941 Nonprimes for which floor(2^n/n) is even.

1, 4, 6, 8, 9, 10, 14, 15, 16, 20, 21, 22, 24, 26, 27, 28, 30, 32, 33, 34, 35, 38, 39, 40, 44, 46, 49, 50, 51, 52, 54, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 81, 82, 84, 85, 86, 87, 88, 90, 92, 93, 94, 96, 102, 104, 105, 106, 111, 114, 115

Offset

1,2

Links

Table of n, a(n) for n=1..68.

Mathematica

Select[ Range[120], EvenQ[ Floor[2^# / # ]] && !PrimeQ[ # ] & ]

Crossrefs

Cf. A071354.

Sequence in context: A073303 A104211 A132858 * A188654 A330991 A180366

Adjacent sequences: A071938 A071939 A071940 * A071942 A071943 A071944

Keyword

nonn

Author

Robert G. Wilson v, Jun 15 2002

Status

approved