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A048985 Working in base 2, replace n by the concatenation of its prime divisors in increasing order (write answer in base 10). 10
1, 2, 3, 10, 5, 11, 7, 42, 15, 21, 11, 43, 13, 23, 29, 170, 17, 47, 19, 85, 31, 43, 23, 171, 45, 45, 63, 87, 29, 93, 31, 682, 59, 81, 47, 175, 37, 83, 61, 341, 41, 95, 43, 171, 125, 87, 47, 683, 63, 173, 113, 173, 53, 191, 91, 343, 115, 93, 59, 349, 61, 95, 127, 2730 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

LINKS

P. De Geest, Home Primes

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

EXAMPLE

15 = 3*5 -> 11.101 -> 11101 = 29, so a(15) = 29.

MATHEMATICA

f[n_] := FromDigits[ Flatten[ IntegerDigits[ Flatten[ Table[ #1, {#2}] & @@@ FactorInteger@n], 2]], 2]; Array[f, 64] [From Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 02 2010]

CROSSREFS

Cf. A037276, A048986, A064841.

Cf. A193652, A029744 (record values and where they occur).

Sequence in context: A130110 A031275 A119023 * A112417 A139693 A175899

Adjacent sequences:  A048982 A048983 A048984 * A048986 A048987 A048988

KEYWORD

nonn,easy,nice,base

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Sam Alexander (pink2001x(AT)hotmail.com) and Michel ten Voorde (seqfan(AT)tenvoorde.org)

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Last modified February 13 06:33 EST 2012. Contains 205448 sequences.