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

Author

Patrick De Geest, Dec 15 1999

Keywords

• nonn
• base

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.

Crossrefs

Cf. A038537, A052027-A052033, A084482, A236356

Programs

Mathematica

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