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A175733 a(n) = the smallest n-digit number with 3 divisors. 6
4, 25, 121, 1369, 10201, 100489, 1018081, 10004569, 100140049, 1000267129, 10000600009, 100008370081, 1000006000009, 10000033772089, 100000380000361, 1000000025191729, 10000001400000049, 100000000621806289, 1000000014000000049, 10000000055856073561 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..20.

FORMULA

a(n) = A131581(n-1)^2.

MATHEMATICA

Table[Prime[1 + PrimePi[Sqrt[10^n]]]^2, {n, 0, 25}] (* T. D. Noe, Aug 19 2011 *)

CROSSREFS

Cf. A131581, A132153, A136582, A175734.

Sequence in context: A069639 A013582 A260373 * A240479 A317949 A263440

Adjacent sequences:  A175730 A175731 A175732 * A175734 A175735 A175736

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Aug 24 2010

STATUS

approved

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Last modified September 20 05:51 EDT 2019. Contains 327212 sequences. (Running on oeis4.)