login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A335664 a(n) = f(n) - f(Sum_{k=1..n-1} a(k)) with a(1) = 1, where f = A000006. 0
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 8 19:28 EDT 2021. Contains 343666 sequences. (Running on oeis4.)