A087009 Least m such that omega(m) + Omega(m) = n, or 0 if no such m exists.

1, 0, 2, 4, 6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072, 6144, 12288, 24576, 49152, 98304, 196608, 393216, 786432, 1572864, 3145728, 6291456, 12582912, 25165824, 50331648, 100663296, 201326592, 402653184, 805306368, 1610612736, 3221225472

Offset: 0

Author

Lekraj Beedassy, Oct 13 2003

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (2).

Crossrefs

First occurrence of n in A080256.

Programs

Mathematica

Join[{1, 0, 2, 4}, LinearRecurrence[{2}, {6}, 40]] (* Jean-François Alcover, Mar 07 2020 *)

PARI

a(n) = {m = 1; while (omega(m) + bigomega(m) != n, m++); m} \\ Michel Marcus, Oct 23 2013

Formula

For n > 3, a(n) = 2^(n-3)*3. - Ray Chandler, Nov 01 2003

a(n) = A058764(n-2). - Philippe Deléham, Oct 17 2011

G.f.: (2*x^4-2*x^2+2*x-1)/(2*x-1). - Colin Barker, Oct 23 2012

Extensions

Corrected and extended by Ray Chandler, Nov 01 2003