A124510 Smallest m such that A124508(m) = A124509(n).

1, 2, 4, 8, 6, 16, 12, 32, 24, 64, 30, 48, 128, 60, 96, 256, 120, 192, 210, 512, 240, 384, 420, 1024, 480, 768, 840, 2048, 960, 2310, 1536, 1680, 4096, 1920, 4620, 3072, 3360, 8192, 3840, 9240, 6144, 6720, 30030, 16384, 7680, 18480, 12288, 13440, 60060, 32768, 15360, 36960, 24576

Offset: 1

Author

Reinhard Zumkeller, Nov 04 2006

Keywords

• nonn
• easy

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002110, A124508, A124509.

Programs

Mathematica

f[n_] := Module[{e2 = IntegerExponent[n, 2], e3 = IntegerExponent[n, 3]}, Product[Prime[i], {i, 1, e3}] * 2^(e2 - e3)];
With[{max = 10^5}, f /@ Join[{1}, Sort[Flatten[Table[2^i*3^j, {i, 1, Log2[max]}, {j, 1, Min[i, Log[3, max/2^i]]}]]]]] (* Amiram Eldar, Jul 11 2023 *)

Formula

A124509(n) = A124508(a(n)).

A124508(k) <> A124508(a(n)) for k < a(n).

a(n) = A002110(e_3) * 2^(e_2-e_3), where e_2 = valuation(A124509(n), 2), and e_3 = valuation(A124509(n), 3).

Extensions

Name corrected and missing terms inserted by Amiram Eldar, Jul 11 2023