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A074493 Numbers n such that all the divisors of n appear as substrings in n^3. 0

%I #9 Feb 11 2014 19:05:30

%S 1,5,25,49,125,251,499,751,1249,4999,18229,31249,49999,281249,4218751,

%T 4999999,9590417,31622777,68171507,74218751,574218751,5740883989,

%U 8829261293

%N Numbers n such that all the divisors of n appear as substrings in n^3.

%e The divisors of 125 are 1, 5, 25, 125, which appear as substrings in 1953125, so 125 is a term of the sequence.

%t a = {}; Do[d = Divisors[i]; l = Length[d]; r = True; s = ToString[i^3]; For[j = 1, j <= l, j++, If[StringPosition[s, ToString[d[[j]]]] == {}, r = False; Break] ]; If[r == True, a = Append[a, i]], {i, 1, 10^5}]; a

%K base,nonn

%O 1,2

%A _Joseph L. Pe_, Sep 25 2002

%E a(15)-a(23) from _Donovan Johnson_, Dec 13 2010

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Last modified April 26 10:21 EDT 2024. Contains 371994 sequences. (Running on oeis4.)