OFFSET
1,2
COMMENTS
If k is power of 6 (k is in A001014), k is in the sequence, but there are also values of other forms; e.g., 68 = 2^2*17.
FORMULA
Numbers k such that ceiling(k^(2/3))^3 - k^2 = ceiling(k^(3/2))^2 - k^3.
Conjectures from Colin Barker, Jun 29 2017: (Start)
G.f.: x*(1 + 57*x - 359*x^2 + 953*x^3 - 888*x^4 + 1352*x^5 - 895*x^6 + 1001*x^7 - 771*x^8 + 325*x^9 - 56*x^10) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n > 11.
(End)
MATHEMATICA
Do[ If[ Ceiling[n^(3/2)]^2 + n^2 == Ceiling[n^(2/3)]^3 + n^3, Print[n]], {n, 1, 5*10^6}]
PROG
(PARI) for(n=1, 130000, if(ceil(n^(3/2))^2-n^3==ceil(n^(2/3))^3-n^2, print1(n, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, May 20 2002
EXTENSIONS
More terms from Robert G. Wilson v, May 27 2002
More terms from Lambert Klasen (lambert.klasen(AT)gmx.de), Dec 23 2004
STATUS
approved