OFFSET
1,1
EXAMPLE
5 = 1^1 + 2^2 = 4^1 + 1^2.
17 = 3^2 + 2^3 = 4^2 + 1^3.
4097 = 1^3 + 8^4 = 16^3 + 1^4.
1048577 = 1^4 + 16^6 = 32^5 + 1^6.
PROG
(PARI) a(n) = my(k=1); while (!(sum(j=1, k^(1/n), (k>j^n)*ispower(k-j^n, n+1))==2), k++); k;
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jun 20 2023
STATUS
approved