A154263
Number of triples such that p+F_s+(F_t)^3=n, where p is an odd prime, s and t are greater than one and F_s or F_t is odd.
Keywords
Examples
For n=14 the a(14)=4 solutions are 3+F_4+(F_3)^3, 5+F_2+(F_3)^3, 5+F_6+(F_2)^3, 11+F_3+(F_2)^3
References
- R. Crocker, On a sum of a prime and two powers of two, Pacific J. Math. 36(1971), 103-107.
- Z. W. Sun and M. H. Le, Integers not of the form c(2^a+2^b)+p^{alpha}, Acta Arith. 99(2001), 183-190.
Links
- Zhi-Wei SUN, Table of n, a(n), n=1..50000.
- D. S. McNeil, Sun's strong conjecture
- Zhi-Wei Sun, A promising conjecture: n=p+F_s+F_t
- Zhi-Wei Sun, A summary concerning my conjecture n=p+F_s+F_t
- K. J. Wu and Z. W. Sun, Covers of the integers with odd moduli and their applications to the forms x^m-2^n and x^2-F_{3n}/2, Math. Comp., in press. arXiv:math.NT/0702382
Programs
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Mathematica
PQ[m_]:=m>2&&PrimeQ[m] RN[n_]:=Sum[If[(Mod[n,2]==0||Mod[x,3]>0)&&PQ[n-(Fibonacci[x])^3-Fibonacci[y]],1,0], {x,2,2*Log[2,n^(1/3)+1]},{y,2,2*Log[2,Max[2,n-(Fibonacci[x])^3]]}] Do[Print[n," ",RN[n]];Continue,{n,1,50000}]
Comments