A071885 -id:A071885 - cp's OEIS frontend

A071884 Trajectory of 37 under map x -> A002487(x)*A002487(x+1).

37, 77, 170, 714, 3450, 10414, 68145, 303610, 721305, 1815066, 17782782, 4598150, 68178460, 133118649, 585506070, 20663527908, 777507763200, 264506067126, 73112062114130, 5907184479605316, 516068243814152148

Offset: 0

N. J. A. Sloane and J. H. Conway, Jun 10 2002

nonn

All smaller starting values lead into a cycle after a small number of steps; this appears to have an infinite trajectory.

Cf. A002487, A071885, A071886, A071887.

# n is starting value, m is length of trajectory to compute
f := proc(n,m) local t1,i,j; t1 := [n]; for i from 2 to m do j := t1[i-1]; t1 := [op(t1), A002487(j)*A002487(j+1)]; od: t1; end;

A071886 Trajectory of 41 under map x -> A002487(x)*A002487(x+1).

Original entry on oeis.org

41, 88, 85, 273, 456, 370, 897, 418, 943, 561, 1240, 2457, 13860, 47652, 208380, 234724, 1687203, 8509066, 67089945, 13299944, 72454532, 940541150, 820208766, 5192523560, 13313765208, 46414871454, 6589784048694, 93614939731600

Offset: 0