A225426 The triples of numbers (a,b,c) that are "abc-hits".

1, 8, 9, 5, 27, 32, 1, 48, 49, 1, 63, 64, 1, 80, 81, 32, 49, 81, 4, 121, 125, 3, 125, 128, 1, 224, 225, 1, 242, 243, 2, 243, 245, 7, 243, 250, 13, 243, 256, 81, 175, 256, 1, 288, 289, 100, 243, 343, 32, 343, 375, 5, 507, 512, 169, 343, 512, 1, 512, 513, 27, 512, 539

Offset

1,2

Comments

Let rad(x) be the function that computes the squarefree kernel of x (see A007947). A triple {a,b,c} of positive integers with a+b=c, gcd(a,b)=1 and c > rad(a*b*c) is called an abc-hit.

Links

T. D. Noe, Table of (a, b, c)(n), n = 1..1269

Wikipedia, abc conjecture

Mathematica

rad[n_] := If[n == 1, 1, Times @@ (Transpose[FactorInteger[n]][[1]])]; nn = 1000; t = {}; r = Table[rad[n], {n, nn}]; Do[If[! PrimeQ[c], Do[b = c - a; If[GCD[a, b] == 1 && r[[a]]*r[[b]]*r[[c]] < c, num++; AppendTo[t, {a, b, c}]], {a, c/2}]], {c, 2, nn}]; t

Crossrefs

Cf. A130510, A130511, A130512 (c, a, and rad(a*b*c)).

Cf. A225425 (number of solutions with c < 10^n).

Sequence in context: A190289 A198119 A088612 * A093626 A154208 A154491

Adjacent sequences: A225423 A225424 A225425 * A225427 A225428 A225429

Keyword

nonn

Author

T. D. Noe, May 22 2013

Status

approved