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A119603
Merging prime factors of n-th composite number.
2
22, 23, 222, 33, 25, 223, 27, 35, 2222, 233, 225, 37, 211, 2223, 55, 213, 333, 227, 235, 22222, 311, 217, 57, 2233, 219, 313, 2225, 237, 2211, 335, 223, 22223, 77, 255, 317, 2213, 2333, 511, 2227, 319, 229, 2235, 231, 337, 222222, 513, 2311, 2217, 323, 257
OFFSET
1,1
COMMENTS
Rule "replace n-th composite number by concatenation of its prime factors" in A037271; composite numbers A002808.
EXAMPLE
a(6)=223 because 6th composite number is 12: A002808(6)=12, then 12=2*2*3 and merging prime factors we get a(6)=223.
MATHEMATICA
Sow[FromDigits@Flatten[Table[IntegerDigits[ #[[1]]], {#[[2]]}]&/@FactorInteger@(n)]]], {n, 2, 115}]][[2, 1]]
CROSSREFS
Sequence in context: A041998 A042000 A042002 * A042004 A042006 A042008
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Jun 03 2006
STATUS
approved