A284606 a(n) = (-1)^n * A284019(n).

0, 0, 0, -1, 0, 0, 1, -1, 1, 0, -1, -1, 0, 0, 2, -1, 1, -1, 0, 0, 0, 1, -2, -2, -1, 1, 1, 0, 0, 0, 4, -1, 0, -2, 2, 1, -1, -1, -1, 1, -1, 1, -1, 2, -2, 3, -3, -5, -4, 4, 1, 2, -4, 0, -1, 3, 1, 1, 0, 0, 0, 0, 8, -1, -2, -4, 0, 3, 2, -2, -1, 1, 0, 2, -2, 3, -1, 4, -4

Offset

1,15

Links

Altug Alkan, Table of n, a(n) for n = 1..10000

Altug Alkan, Alternative Scatterplot of A284606

Formula

a(n) = (-1)^n * (A004001(n) - A005185(n)).

Example

a(4) = -1 since a(4) = (-1)^4 * (A004001(4) - A005185(4)) = 2 - 3 = -1

Maple

A005185:= proc(n) option remember; procname(n-procname(n-1)) +procname(n-procname(n-2)) end proc:
A005185(1):= 1: A005185(2):= 1:
A004001:= proc(n) option remember; procname(procname(n-1)) +procname(n-procname(n-1)) end proc:
A004001(1):= 1: A004001(2):= 1:
A284606:= map((-1)^i * (A004001 - A005185), [$1..1000]):
seq(A284606[i], i=1..1000); # Altug Alkan, Apr 01 2017

Mathematica

a[n_] := a[n] = If[n <= 2, 1, a[a[n - 1]] + a[n - a[n - 1]]]; b[1] = b[2] = 1; b[n_] := b[n] = b[n - b[n - 1]] + b[n - b[n - 2]]; Table[(-1)^n*(a@ n - b@ n), {n, 87}] (* Michael De Vlieger, Apr 02 2017, after Robert G. Wilson v at A004001 *)

Prog

(PARI) q=vector(10000); h=vector(10000); q[1]=q[2]=1; for(n=3, #q, q[n]=q[n-q[n-1]]+q[n-q[n-2]]); h[1]=h[2]=1; for(n=3, #h, h[n]=h[h[n-1]]+h[n-h[n-1]]); vector(10000, n, (-1)^n*(h[n]-q[n]))

Crossrefs

Cf. A004001, A005185, A284019.

Sequence in context: A015318 A026836 A089052 * A284019 A286135 A142475

Adjacent sequences: A284603 A284604 A284605 * A284607 A284608 A284609

Keyword

sign,look

Author

Altug Alkan, Mar 30 2017

Status

approved