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A046464 Concatenation of numbers from 1 to a(n) has exactly 5 prime factors, with multiplicity. 1
8, 17, 25, 41, 47, 55, 56, 63 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..8.

M. Fleuren, Factors and primes of Smarandache sequences.

M. Fleuren, Smarandache Factors and Reverse factors

P. De Geest, Normal Smarandache Concatenated Numbers, Prime factors from 1 up to n

C. Rivera, Primes by Listing

CROSSREFS

Cf. A007908, A046460, A050682.

Sequence in context: A118066 A044060 A121283 * A022390 A041831 A041122

Adjacent sequences:  A046461 A046462 A046463 * A046465 A046466 A046467

KEYWORD

nonn,hard,base

AUTHOR

Patrick De Geest, Aug 15 1998.

STATUS

approved

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Last modified December 18 18:07 EST 2018. Contains 318243 sequences. (Running on oeis4.)