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A182679
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a(n) = the smallest n-digit number with exactly 10 divisors, a(n) = 0 if no such number exists.
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2
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0, 48, 112, 1053, 10096, 100112, 1000016, 10000017, 100000144, 1000000016, 10000000071, 100000000336, 1000000000304, 10000000000624, 100000000000528, 1000000000000016, 10000000000000503
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OFFSET
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1,2
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COMMENTS
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a(n) = the smallest n-digit number of the form p^9 or p^4*q^1 (p, q = distinct primes), a(n) = 0 if no such number exists.
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LINKS
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FORMULA
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MATHEMATICA
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Table[k=10^(n-1); While[k<10^n && DivisorSigma[0, k] != 10, k++]; If[k==10^n, k=0]; k, {n, 10}]
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PROG
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(Sage) A182679 = lambda n: next((x for x in IntegerRange(10**(n-1), 10**n) if number_of_divisors(x) == 10), 0)
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CROSSREFS
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See A182680(n) - the largest n-digit number with exactly 10 divisors.
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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