A385233 Numbers that can be written as s^x + t^y + u^z with 1 < s < t < u and {s,t,u} = {x,y,z} (the sequence of exponents can be any permutation of s,t,u).

59, 84, 89, 105, 127, 149, 166, 204, 273, 276, 287, 289, 313, 347, 356, 372, 433, 480, 576, 620, 624, 673, 773, 777, 849, 932, 949, 1065, 1151, 1201, 1230, 1250, 1376, 1380, 1653, 1676, 2033, 2089, 2196, 2244, 2425, 2534, 2545, 2786, 3142, 3156, 3157, 3225, 3270, 3302, 3385, 3388, 3408, 3445, 3718, 4070, 4148, 4249

Offset

1,1

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Alberto Zanoni, BE-numbers

A. Zanoni and M. Zanoni, Sums of bases-exponents positive integer powers, Analele ştiinţifice ale Universităţii "Ovidius" Constanţa, 34-2 (2026), 197-210.

Example

a(1) = 2^4 + 3^3 + 4^2 = 16 + 27 + 16 =  59.
a(2) = 2^5 + 3^3 + 5^2 = 32 + 27 + 25 =  84.
a(3) = 2^4 + 3^2 + 4^3 = 16 +  9 + 64 =  89.
a(4) = 2^3 + 3^4 + 4^2 =  8 + 81 + 16 = 105.

Crossrefs

Cf. A001597, A385232 (two addends).

Sequence in context: A068209 A139958 A097459 * A145291 A136076 A186399

Adjacent sequences: A385230 A385231 A385232 * A385234 A385235 A385236

Keyword

nonn,changed

Author

Alberto Zanoni, Jun 28 2025

Status

approved