|
Search: id:A145195
|
|
|
| A145195 |
|
Odd composite numbers n with proprty that at least one prime divisor p of n is a substring of the binary representation of n. |
|
+0
1
|
|
| 15, 27, 39, 45, 51, 55, 57, 63, 75, 85, 87, 91, 93, 95, 99, 105, 111, 117, 119, 123, 125, 135, 141, 147, 153, 155, 159, 165, 171, 175, 177, 183, 185, 187, 189, 195, 201, 205, 207, 213, 215, 219, 221, 225, 231, 235, 237, 243, 245, 247, 249, 255, 267, 279, 285
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
It is obvious that all even numbers and all prime numbers would meet this criteria.
|
|
MATHEMATICA
|
f[n_] := Block[{nb = ToString@ FromDigits@ IntegerDigits[n, 2], psb = ToString@ FromDigits@ IntegerDigits[ #, 2] & /@ First@ Transpose@ FactorInteger@n, c = 0, k = 1}, lmt = 1 + Length@ psb; While[k < lmt, If[ StringCount[nb, psb[[k]]] > 0, c++ ]; k++ ]; c]; f[1] = 0; Select[ Range@ 286, !PrimeQ@ # && OddQ@ # && f@# > 0 &]
|
|
CROSSREFS
|
Cf. A014076, A143791.
Sequence in context: A110703 A091236 A053177 this_sequence A096022 A097222 A004069
Adjacent sequences: A145192 A145193 A145194 this_sequence A145196 A145197 A145198
|
|
KEYWORD
|
easy,nonn,base
|
|
AUTHOR
|
Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 03 2008
|
|
|
Search completed in 0.002 seconds
|
