login
A206476
Numbers n such that n^5 = a^2 + b^3 + c^5 for some positive integers a, b, and c.
0
2, 6, 8, 9, 10, 11, 12, 13, 14, 18, 19, 20, 21, 24, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69
OFFSET
1,1
COMMENTS
Some can be expressed in more than one way.
EXAMPLE
10^5 = 168^2 + 40^3 + 6^5 = 280^2 + 24^3 + 6^5.
PROG
(Maxima) isA206476(n) := block(
[a, b, c, v],
v : false ,
for c : 1 while c < n and not v do (
for b : 1 while b^3+c^5 < n^5 and not v do (
for a : isqrt(n^5-c^5-b^3) while a^2+b^3+c^5 <= n^5 and not v do (
if equal(a^2+b^3+c^5, n^5) then v : true
)
)
),
return(v)
)$
for n : 1 thru 100 do (
if equal(isA206476(n), true ) then print(n)
)$ /* R. J. Mathar, Feb 27 2012 */
CROSSREFS
Sequence in context: A320573 A003610 A201776 * A077477 A095879 A342751
KEYWORD
nonn
AUTHOR
Carmine Suriano, Feb 08 2012
STATUS
approved