OFFSET
1,1
COMMENTS
There are 434 terms < 6 * 10^7 of which the largest is 5042631 ~= 5 * 10^6. Is this sequence finite? - David A. Corneth, Jun 23 2018
No more terms < 10^10. - Mauro Fiorentini, Jan 26 2019
For n = 1..434, a(n) + 2 is a term of A022551. Zhi-Wei Sun conjectures that Any n can be written as x^2 + y^2 + z^3 + 0(or 2). - XU Pingya, Jun 02 2020
LINKS
R. J. Mathar, David A. Corneth, Table of n, a(n) for n = 1..434 (First 325 terms from R. J. Mathar, now terms < 6 * 10^7)
Steven Finch, Pattern-Avoiding Permutations [Broken link?]
Steven Finch, Pattern-Avoiding Permutations [Cached copy, with permission]
W. Jagy and I. Kaplansky, Sums of Squares, Cubes and Higher Powers, Experimental Mathematics, vol. 4 (1995) pp. 169-173.
Zhi-Wei Sun, New Conjectures on Representations of Integers (I), Nanjing Univ. J. Math. Biquarterly 34(2017), No.2, p. 110.
MAPLE
isA022552 := proc(n)
not isA022551(n) ;
end proc:
n := 1:
for c from 0 do
if isA022552(c) then
printf("%d %d\n", n, c);
n := n+1 ;
end if;
end do: # R. J. Mathar, Sep 02 2016
MATHEMATICA
max = 10^6;
Table[x^2 + y^2 + z^3, {x, 0, Sqrt[max]}, {y, x, Sqrt[max - x^2]}, {z, 0, (max - x^2 - y^2)^(1/3)}] // Flatten // Union // Select[#, # <= max&]& // Complement[Range[max], #]& (* Jean-François Alcover, Mar 23 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved