A354447 Taxicab numbers (sums of 2 cubes in more than 1 way) which are products of four distinct primes.

684019, 704977, 2691451, 3242197, 3375001, 4931101, 5318677, 5772403, 8872487, 10702783, 16983854, 20616463, 24897817, 41258737, 46343059, 60698521, 66469429, 69625969, 79692193, 89576767, 95731489, 96753187, 97867441, 116773741, 119793457, 126516061, 147187369

Offset: 1

Author

Massimo Kofler, May 30 2022

Keywords

• nonn

Comments

A squarefree subsequence of taxicab numbers.

Examples

			684019 =  51^3 +  82^3 =  64^3 +  75^3 =  7 * 19 *  37 *  139.
8872487 =  14^3 + 207^3 = 140^3 + 183^3 = 13 * 17 *  19 * 2113.
96753187 = 147^3 + 454^3 = 283^3 + 420^3 = 19 * 37 * 229 *  601.
		

Links

• Eric Weisstein's World of Mathematics, Taxicab Number

Crossrefs

Intersection of A001235 and A046386.

Programs

Mathematica

Select[Range[10^6], FactorInteger[#][[;; , 2]] == {1, 1, 1, 1} && Length @ PowersRepresentations[#, 2, 3] > 1 &] (* Amiram Eldar, May 30 2022 *)