1,2

A137671(a(n)) = 1; A137672(a(n))=1;

for n>1: A137671(a(n)-1) = 2^(n-1)-1 = A000225(n-1); A137672(a(n)-1) = n-1;

a(n) = A137673(A137671(a(n)-1)) + 1.

Sequence in context: A029885 A114298 A112839 this_sequence A048781 A097919 A054657

Adjacent sequences: A137671 A137672 A137673 this_sequence A137675 A137676 A137677

nonn

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Febr 05 2008