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 A048985 Working in base 2, replace n with 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; text; internal format)
 OFFSET 1,2 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 P. De Geest, Home Primes 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] (* Robert G. Wilson v, Jun 02 2010 *) PROG (Haskell) -- import Data.List (unfoldr) a048985 = foldr (\d v -> 2 * v + d) 0 . concatMap    (unfoldr (\x -> if x == 0 then Nothing else Just \$ swap \$ divMod x 2))    . reverse . a027746_row -- Reinhard Zumkeller, Jul 16 2012 CROSSREFS Cf. A037276, A048986, A064841. Cf. A193652, A029744 (record values and where they occur). Cf. A027746. Sequence in context: A213962 A216937 A230625 * A337183 A112417 A139693 Adjacent sequences:  A048982 A048983 A048984 * A048986 A048987 A048988 KEYWORD nonn,easy,nice,base,look AUTHOR EXTENSIONS More terms from Sam Alexander (pink2001x(AT)hotmail.com) and Michel ten Voorde STATUS approved

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Last modified April 14 22:43 EDT 2021. Contains 342963 sequences. (Running on oeis4.)