A335664 a(n) = f(n) - f(Sum_{k=1..n-1} a(k)) with a(1) = 1, where f = A000006.

1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 2, 1, 0, 0, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 2, 1, 1, 0, 0, 1, 1, 1, 1, 2, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

1,12

Links

Table of n, a(n) for n=1..100.

Mathematica

f[n_] := IntegerPart[Sqrt[Prime[n]]]; a[1] = 1; a[n_] := a[n] = f[n] - f[Sum[a[k], {k, 1, n - 1}]]; Array[a, 100] (* Amiram Eldar, Jul 09 2020 *)

Prog

(PARI) a=vector(10^2); a[1] = 1; for(n=2, #a, a[n] = sqrtint(prime(n)) - sqrtint(prime(sum(k=1, n-1, a[k])))); a

Crossrefs

Cf. A000006, A335294.

Sequence in context: A333382 A143379 A254605 * A269518 A219840 A343220

Adjacent sequences: A335661 A335662 A335663 * A335665 A335666 A335667

Keyword

nonn,easy

Author

Altug Alkan, Jul 09 2020

Status

approved