A386892 Numbers k expressible as x^y + y^z + z^x, where x, y, and z are integers > 1.

12, 21, 36, 44, 61, 81, 89, 104, 105, 166, 172, 181, 276, 288, 289, 324, 395, 401, 480, 597, 673, 768, 773, 777, 932, 972, 1065, 1128, 1230, 1250, 1376, 1905, 2033, 2089, 2173, 2244, 2545, 2557, 3182, 3388, 3493, 4148, 4244, 4368, 4393, 4652, 4774

Offset

1,1

Links

Andrew Howroyd, Table of n, a(n) for n = 1..10000

Example

a(7) = 89, which can be given by x=4, y=3, z=2.

Prog

(PARI) upto(lim) = { my(L=List()); for(x=2, logint(lim, 2), for(y=2, min(x, logint(lim, x)), for(z=2, min(x, logint(lim, y)), my(t=x^y+y^z+z^x); if(t<=lim, listput(L, t)) ))); Set(L) } \\ Andrew Howroyd, Aug 06 2025

Crossrefs

Cf. A123207 (subsequence of primes).

Cf. A076980.

Sequence in context: A071263 A241503 A226186 * A325301 A351478 A219542

Adjacent sequences: A386889 A386890 A386891 * A386893 A386894 A386895

Keyword

nonn

Author

Ian Hahus, Aug 06 2025

Status

approved