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A067205 Least numbers with n = digital root = number of prime factors. 0
19, 38, 12, 40, 32, 96, 448, 1664, 1152 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

For 1 <= n <= 9: A010888(a(n)) = A001222(a(n)) = n.

EXAMPLE

a(7)=448 as A001222(448)=7 because of 448=2*2*2*2*2*2*7

and A010888(448)=7 because of 4+4+8=16 and 1+6=7.

CROSSREFS

Cf. A007953.

Sequence in context: A111441 A144594 A123028 * A196185 A040342 A164009

Adjacent sequences:  A067202 A067203 A067204 * A067206 A067207 A067208

KEYWORD

nonn,base,fini,full

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 19 2002

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Last modified February 15 12:25 EST 2012. Contains 205786 sequences.