login
A393032
Numbers that can be written in exactly five ways as s_1^x_1 + ... + s_t^x_t, with 0 < s_1 < ... < s_t and x_1 > ... > x_t > 1 for some t > 0, with the restriction that if s_1 = 1 then x_1 is the least possible.
10
108, 161, 162, 164, 165, 192, 213, 228, 229, 241, 242, 246, 266, 274, 281, 288, 292, 293, 299, 309, 314, 322, 330, 351, 352, 382, 383, 397, 414, 415, 428, 432, 443, 444, 446, 458, 471, 474, 479, 484, 485, 495, 498, 502, 507, 509, 523, 524, 527, 530, 535, 544, 555, 571, 585, 603, 605
OFFSET
1,1
COMMENTS
Conjecture: The sequence is finite and its last number is 2879.
LINKS
EXAMPLE
108 = 2^3 + 10^2 = 3^3 + 9^2 = 2^5 + 3^3 + 7^2 = 1^5 + 2^4 + 3^3 + 8^2
= 1^7 + 2^6 + 3^3 + 4^2;
161 = 5^3 + 6^2 = 1^5 + 2^4 + 12^2 = 2^4 + 4^3 + 9^2 = 2^6 + 3^4 + 4^2
= 1^6 + 2^5 + 4^3 + 8^2;
162 = 3^4 + 9^2 = 1^4 + 5^3 + 6^2 = 2^5 + 3^4 + 7^2
= 1^7 + 2^6 + 3^4 + 4^2 = 1^5 + 2^4 + 4^3 + 9^2;
...
KEYWORD
nonn
AUTHOR
Alberto Zanoni, Jan 31 2026
STATUS
approved