A061153 Numbers k such that k*2^m+1 are composites for all exponents m in the range 0<=m<=k.

47, 94, 188, 257, 376, 383, 766, 881, 1532, 2897, 3061, 3064, 4847, 5297, 5359, 5794, 5897, 6122, 6128, 7013, 7651, 8423, 9694, 10223, 10594, 10718, 11794, 12244, 13787, 14026, 14027, 15302, 16817, 16846, 18107, 19249, 19388, 20446, 21181, 21188

Offset

1,1

Links

Table of n, a(n) for n=1..40.

Maple

filter:= n -> andmap(not isprime, [seq(n*2^m+1, m=0..n)]):
select(filter, [$1..10000]); # Robert Israel, Sep 22 2019

Crossrefs

Cf. A061154, A061155, A061156, A061157, A061158.

Sequence in context: A217355 A004943 A004963 * A335076 A044185 A044566

Adjacent sequences: A061150 A061151 A061152 * A061154 A061155 A061156

Keyword

nonn

Author

Patrick De Geest, Apr 15 2001

Extensions

More terms from Robert Israel, Sep 22 2019

Offset corrected by Sean A. Irvine, Jan 22 2023

Status

approved