A052026 Composites base 10 that remain composite in all bases b, 2<=b<=10, expansions interpreted as decimal numbers.

14, 18, 20, 24, 30, 32, 36, 40, 42, 44, 51, 54, 60, 62, 69, 70, 72, 74, 76, 78, 80, 86, 90, 92, 96, 98, 99, 100, 102, 104, 108, 110, 112, 114, 120, 124, 125, 126, 128, 129, 130, 132, 135, 140, 144, 146, 148, 150, 152, 156, 158, 159, 160, 162, 164, 168, 170, 174

Offset

1,1

Links

Sebastian Petzelberger, Table of n, a(n) for n = 1..10000

Carlos Rivera, Puzzle 24. Primes in several bases, The Prime Puzzles & Problems Connection.

Mathematica

Select[Range@ 174, AllTrue[Table[FromDigits[IntegerDigits[#, i]], {i, 2, 10}], CompositeQ] &] (* Michael De Vlieger, Mar 24 2015, version 10 *)

Crossrefs

Cf. A038537, A052027-A052033, A084482, A236356

Sequence in context: A063828 A365792 A060504 * A317743 A118499 A111205

Adjacent sequences: A052023 A052024 A052025 * A052027 A052028 A052029

Keyword

nonn,base

Author

Patrick De Geest, Dec 15 1999

Status

approved