A063145 Composite numbers not divisible by 2 which in base 4 contain their largest proper factor as a substring.

407, 1189, 1343, 1681, 7597, 8791, 10579, 16147, 23479, 24341, 25751, 26101, 28757, 34093, 36349, 39961, 47053, 47669, 52891, 58879, 62263, 64277, 79223, 88183, 93829, 96029, 98261

Offset

1,1

Links

Table of n, a(n) for n=1..27.

Mathematica

Do[ If[ !PrimeQ[ n ] && StringPosition[ ToString[ FromDigits[ IntegerDigits[ n, 4 ] ] ], ToString[ FromDigits[ IntegerDigits[ Divisors[ n ][ [ -2 ] ], 4 ] ] ] ] != {}, Print[ n ] ], {n, 3, 10^5, 2} ]

Crossrefs

Cf. A062238.

Sequence in context: A118327 A213606 A343157 * A281859 A067674 A157263

Adjacent sequences: A063142 A063143 A063144 * A063146 A063147 A063148

Keyword

base,nonn

Author

Robert G. Wilson v, Aug 08 2001

Status

approved