1,2

Much like the Hofstadter Q-sequence A005185, it is not known if this sequence is defined for all positive n.

Empirically, this sequence appears to grow approximately like n/2 with a lot of noise.

a(n) exists for n<=10^7.

Nathan Fox, Table of n, a(n) for n = 1..10000

#Code for A272611, A272612, and A272613

A272611:=proc(n) option remember:

if n = 1 then

return 1:

else

return A272611(n-A272611(n-1))+A272612(n-1):

fi:

end:

A272612:=proc(n) option remember:

if n = 0 then

elif n = 1 then

return A272612(n-A272611(n))+A272612(n-A272611(n-1)):

A272613:=proc(n) option remember:

return A272613(n-A272611(n))+A272613(n-A272612(n)):

Cf. A005185, A272610, A272612, A272613.

Sequence in context: A143091 A114539 A238746 * A156562 A290736 A007998

Adjacent sequences: A272608 A272609 A272610 * A272612 A272613 A272614

nonn

Nathan Fox, May 03 2016

approved