A271473 a(1)=0; thereafter a(2k)=k+a(k), a(2k+1)=k+a(6k+4).

0, 1, 23, 3, 17, 26, 141, 7, 166, 22, 127, 32, 58, 148, 344, 15, 105, 175, 256, 32, 73, 138, 314, 44, 325, 71, 50699, 162, 218, 359, 50532, 31, 416, 122, 268, 193, 264, 275, 1166, 52, 50645, 94, 664, 160, 246, 337, 50470, 68, 399, 350, 561, 97, 198, 50726, 51137, 190, 821, 247, 1088, 389

Offset

1,3

Comments

Inspired by A266569.

Links

Robert Price, Table of n, a(n) for n = 1..1000

Maple

A271473 := proc(n)
        local a, traj ;
        a := 0 ;
        traj := n ;
        while traj > 1 do
                if type(traj, 'even') then
                        a:=a+traj/2;
                        traj := traj/2 ;
                else
                        a:=a+(traj-1)/2;
                        traj := 3*traj+1 ;
                end if;
        end do:
        return a;
end proc:
[seq(A271473(n), n=1..60)];

Mathematica

a[1]=0; a[n_] := a[n] = If[EvenQ[n], n/2 + a[n/2], (n - 1)/2 + a[3*(n - 1) + 4]]; Array[a, 60] (* Robert Price, Apr 08 2016 *)

Crossrefs

Cf. A266569, A270814.

Sequence in context: A040517 A040519 A040520 * A317323 A040515 A040516

Adjacent sequences: A271470 A271471 A271472 * A271474 A271475 A271476

Keyword

nonn

Author

N. J. A. Sloane, Apr 08 2016

Status

approved