A385232 Numbers that can be written as s^x + t^y, with 1 < s < t and {s,t} = {x,y}; that is, are of the form s^s + t^t or s^t + t^s.

17, 31, 32, 57, 100, 145, 177, 260, 283, 320, 368, 593, 945, 1124, 1649, 2169, 2530, 3129, 3152, 3381, 4240, 5392, 7073, 8361, 16580, 18785, 20412, 23401, 32993, 46660, 46683, 46912, 49781, 60049, 65792, 69632, 94932, 131361, 178478, 262468, 268705, 397585, 423393, 524649, 533169, 823547, 823570

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) = 2^3 + 3^2 =  8 +  9 = 17.
a(2) = 2^2 + 3^3 =  4 + 27 = 31.
a(3) = 2^4 + 4^2 = 16 + 16 = 32.
a(4) = 2^5 + 5^2 = 32 + 25 = 57.

Crossrefs

Cf. A000312, A001597, A385233 (three addends).

Union of A173054 and A385614.

Sequence in context: A124884 A052006 A002675 * A333855 A321217 A095748

Adjacent sequences: A385229 A385230 A385231 * A385233 A385234 A385235

Keyword

nonn,easy,changed

Author

Alberto Zanoni, Jun 28 2025

Status

approved