A283673 a(n) = lcm(q(n - q(n+1) + 2), q(n - q(n) + 2)) where q(n) = A005185(n).

1, 2, 2, 2, 6, 6, 3, 3, 3, 4, 15, 4, 5, 20, 5, 30, 30, 6, 6, 6, 6, 8, 24, 24, 8, 8, 8, 8, 10, 72, 72, 10, 110, 90, 99, 11, 110, 11, 132, 132, 12, 12, 12, 12, 12, 16, 70, 154, 112, 48, 84, 112, 112, 14, 16, 112, 16, 16, 16, 16, 20, 272, 238, 357, 304, 272, 380, 20, 340, 357, 399

Offset: 1

Author

Altug Alkan, Mar 14 2017

Keywords

• nonn
• look

Comments

See the order of chaotic subsequences in scatterplot link.

Examples

			a(4) = lcm(A005185(4 - A005185(5) + 2), A005185(4 - A005185(4) + 2)) = lcm(A005185(3), A005185(3)) = lcm(2, 2) = 2.
		

Links

• Altug Alkan, Table of n, a(n) for n = 1..10000
• Altug Alkan, Alternative Scatterplot of A283673

Crossrefs

Cf. A005185, A283672, A283677.

Programs

Mathematica

q[1] = q[2] = 1; q[n_] := q[n] = q[n - q[n - 1]] + q[n - q[n - 2]]; Table[LCM[q[n - q[n + 1] + 2], q[n - q[n] + 2]], {n, 71}] (* Indranil Ghosh, Mar 14 2017 *)

PARI

a=vector(1001); a[1]=a[2]=1; for(n=3, #a, a[n]=a[n-a[n-1]]+a[n-a[n-2]]); va = vector(1000, n, lcm(a[n+2-a[n+1]],a[n+2-a[n]]))