1,2

If A072010(n)=n then also A072010(n*3^i)=n and A072010(n*2^j)=n*2^j;

for m=(4*k+1)*(4*k+3), product of twin prime pairs: A072010(m)=m, as well as for values m in the free monoid generated by the range of A071697.

395675 is a term as f(395675) = f(323*1225) = f((17*19)*(5*7)^2) = f(17*19)*(f(5*7))^2 = f(17)*f(19)*(f(5)*f(7))^2 = 19*17*(7*5)^2 = 323*1225 = 395675 for f=A072010.

Cf. A002144, A002145, A071695, A071696.

Adjacent sequences: A072008 A072009 A072010 this_sequence A072012 A072013 A072014

Sequence in context: A115423 A141031 A045603 this_sequence A068535 A051505 A101434

nonn

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 05 2002