A094380 Greatest number having exactly n representations as ab+ac+bc with 1 <= a <= b <= c.

462, 142, 742, 862, 2170, 2062, 3502, 2962, 5278, 5413, 7282, 8002, 11302, 11278, 14722, 13918, 18778, 21058, 30178, 30493, 30622, 34318, 47338, 31102, 44902, 43717

Offset

0,1

Comments

Numbers up to 250,000 were checked. Note that the Mathematica program computes A094379, A094380 and A094381, but outputs only this sequence.

References

See A025052

Links

Table of n, a(n) for n=0..25.

Example

a(1) = 142 because 142 is the largest number with a unique representation: (a,b,c) = (1,10,12).

Mathematica

cntMax=10; nSol=Table[{0, 0, 0}, {cntMax+1}]; Do[lim=Ceiling[(n-1)/2]; cnt=0; Do[If[n>a*b && Mod[n-a*b, a+b]==0 && Quotient[n-a*b, a+b]>=b, cnt++; If[cnt>cntMax, Break[]]], {a, 1, lim}, {b, a, lim}]; If[cnt<=cntMax, If[nSol[[cnt+1, 1]]==0, nSol[[cnt+1, 1]]=n]; nSol[[cnt+1, 2]]=n; nSol[[cnt+1, 3]]++; ], {n, 10000}]; Table[nSol[[i, 2]], {i, cntMax+1}]

Crossrefs

Cf. A025052 (n having no representations), A093670 (n having one representation), A094379, A094381.

Sequence in context: A059025 A267200 A348899 * A267404 A267343 A267396

Adjacent sequences: A094377 A094378 A094379 * A094381 A094382 A094383

Keyword

nonn

Author

T. D. Noe, Apr 28 2004

Status

approved