A256354 Composites in base 10 that remain composite in exactly four bases b, 2 <= b <= 10, expansions interpreted as decimal numbers.

115, 2563, 3523, 5071, 9193, 10873, 12223, 12811, 13231, 15775, 19111, 20203, 23089, 25831, 27007, 28171, 34189, 39859, 40033, 43361, 55033, 57871, 58813, 74371, 84253, 89377, 93043, 95833, 101683, 117001, 125359, 126673, 128953, 131029, 134527, 137467, 138193

Offset: 1

Author

Sebastian Petzelberger, Mar 25 2015

Keywords

• nonn
• base

Links

• Sebastian Petzelberger, Table of n, a(n) for n = 1..10000
• Carlos Rivera, PP&P Puzzle 24: Primes in several bases

Crossrefs

Cf. A052026, A256350-A256356, A038537, A052027-A052033, A084482, A236356.