A308576 a(n) = a(n-1) + a(a(n-1) mod n) + 1, a(0) = 1.

1, 3, 7, 11, 23, 35, 71, 75, 87, 159, 319, 321, 481, 483, 559, 583, 659, 1143, 1303, 1625, 1661, 1669, 3295, 3367, 3443, 4747, 5331, 5813, 6957, 12289, 13915, 19729, 20873, 22017, 23643, 24947, 49895, 51521, 71251, 122773, 123257, 123579, 124163, 127459, 152407

Offset

0,2

Links

Table of n, a(n) for n=0..44.

Formula

a(n) = a(n-1) + a(a(n-1) mod n) + 1, a(0) = 1.

Maple

a:= proc(n) option remember; `if`(n=0, 1,
      a(n-1) + a(a(n-1) mod n) + 1)
    end:
seq(a(n), n=0..50); # Alois P. Heinz, Jul 08 2019

Mathematica

a[0]=1; a[n_] := a[n] = a[n-1] + a[Mod[a[n-1], n]] + 1; Array[a, 50, 0] (* Amiram Eldar, Jul 08 2019 *)

Prog

(Java)
int f(int n) {
   int[] a = new int[n + 1];
   a[0] = 1;
   for (int i = 1; i < n + 1; i++) a[i] = a[i - 1] + a[a[i - 1] % i] + 1;
   return a[n];
}
(Haskell)
a 0 = 1
a n = (a (n - 1)) + (a (a (n - 1) `mod` n)) + 1
(PARI) getV(n, v) = if (!v[n+1], v[n+1] = getV(n-1, v) + getV(getV(n-1, v) % n, v) + 1); v[n+1];
lista(nn) = {my(v=vector(nn+1)); v[1] = 1; for (n=1, nn, v[n+1] = getV(n, v); ); v; } \\ Michel Marcus, Jun 09 2019

Crossrefs

Sequence in context: A192614 A112715 A106935 * A116362 A090918 A139253

Adjacent sequences: A308573 A308574 A308575 * A308577 A308578 A308579

Keyword

nonn

Author

Artem Yashin, Jun 08 2019

Extensions

More terms from Michel Marcus, Jun 09 2019

Status

approved