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A063145 Composite numbers not divisible by 2 which in base 4 contain their largest proper factor as a substring. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified January 20 10:09 EST 2022. Contains 350471 sequences. (Running on oeis4.)