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 A118663 Index of the least prime dividing the n-th composite number: A000720(A020639(A002808(n))). 2
 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 3, 1, 1, 2, 1, 1, 1, 2, 1, 1, 4, 1, 2, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 3, 1, 1, 2, 1, 1, 1, 2, 1, 4, 1, 1, 2, 1, 1, 3, 1, 2, 1, 1, 4, 1, 2, 1, 3, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 3, 1, 2, 1, 4, 1, 5, 1, 2, 1, 3, 1, 1, 2, 1, 1, 4, 1, 2, 1, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS FORMULA A118663 = A000720 o A056608. - M. F. Hasler, Apr 03 2012 PROG (PARI) for(i=2, 999, isprime(i)||print1(primepi(factor(i)[1, 1])", ")) \\ - M. F. Hasler, Apr 03 2012 CROSSREFS Cf. A056608. Sequence in context: A161100 A053543 A161099 * A205119 A293234 A102097 Adjacent sequences:  A118660 A118661 A118662 * A118664 A118665 A118666 KEYWORD easy,nonn AUTHOR Giovanni Teofilatto, May 19 2006 STATUS approved

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