A038840 -id:A038840 - cp's OEIS frontend

A166533 Numbers whose cube is a concatenation of exactly three primes (leading zeros allowed).

13, 15, 18, 29, 33, 38, 39, 43, 45, 48, 55, 59, 63, 68, 73, 83, 91, 95, 98, 103, 108, 111, 117, 125, 131, 137, 148, 149, 161, 163, 171, 173, 175, 177, 179, 217, 233, 235, 237, 241, 258, 259, 275, 278, 289, 293, 295, 297, 321, 337, 339, 357, 377, 378, 388, 391

Offset: 1

Zak Seidov, Oct 16 2009

The three primes are not necessarily all distinct. All even terms k are == 8 (mod 10) (and hence k^3 == 2 (mod 10)).

			13^3 =   2197 => { 2,  19,  7};
15^3 =   3375 => { 3,  37,  5};
18^3 =   5832 => { 5,  83,  2};
43^3 =  79507 => {79,   5, 07} (first case with leading zero);
48^3 = 110592 => {11, 059,  2} (next case with leading zero).

Cf. A166534 (version with leading zeros not allowed), A038840 Cubes that are concatenations of primes.

s={};Do[id=IntegerDigits[n^3];Le=Length@id; Do[t=FromDigits/@{Take[id,k],Take[id,{k+1,m}],Take[id,m-Le]}; If[PrimeQ[t]=={True,True,True},AppendTo[s,n];Goto[ne]],{k,Le-2},{m,k+1,Le-1}];Label[ne],{n,5,800}];s

Edited by Charles R Greathouse IV, Mar 23 2010

A166534 Numbers n with property that n^3 is concatenation of exactly three primes: leading zeros not allowed.

Original entry on oeis.org

13, 15, 18, 29, 33, 38, 39, 45, 55, 68, 83, 91, 95, 98, 103, 108, 111, 117, 125, 131, 137, 148, 161, 163, 173, 175, 177, 179, 217, 233, 235, 237, 241, 258, 259, 278, 289, 293, 295, 297, 321, 337, 339, 357, 377, 378, 391, 395, 409, 415, 417, 418, 421, 433, 453

Offset: 1

Zak Seidov, Oct 16 2009

Subsequence of A166533.

			13^3=2197=>{2,19,7}
15^3=3375=>{3,37,5}
18^3=5832=>{5,83,2}.

Cf. A166533 (version with leading zeros allowed), A038840 Cubes that are concatenations of primes.

Edited by Charles R Greathouse IV, Mar 23 2010

cp's OEIS Frontend

A166533 Numbers whose cube is a concatenation of exactly three primes (leading zeros allowed).

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