A063905 Each prime p appears p times.

2, 2, 3, 3, 3, 5, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19

Offset: 1

Author

Reinhard Zumkeller, Aug 30 2001

Keywords

• nonn
• easy

Comments

a(A007504(k)) = prime(k) and a(A007504(k) + 1) = prime(k + 1) for k > 0, where prime = A000040.

Examples

			a(A007504(4)) = prime(4) = 7 = a(17) and a(18) = a(A007504(4)+1) = prime(4+1) = prime(5) = 11.
		

Links

• Harry J. Smith, Table of n, a(n) for n=1,...,1000

Crossrefs

Cf. A007504, A002024, A000040, A175944.

Programs

Haskell

a063905 n = a063905_list !! (n-1)
a063905_list =
   concat $ zipWith ($) (map replicate a000040_list) a000040_list
-- Reinhard Zumkeller, Mar 18 2011

Mathematica

Flatten[Table[Prime[n], {n, 8}, {Prime[n]}]] (* Alonso del Arte, Sep 08 2011 based on Robert G. Wilson v's program for A002024 *)
Table[PadRight[{},p,p],{p,Prime[Range[8]]}]//Flatten (* Harvey P. Dale, Mar 13 2023 *)

PARI

{ n=0; p=1; for (m=1, 10^9, p=nextprime(p+1); for (i=1, p, write("b063905.txt", n++, " ", p); if (n==1000, break)); if (n==1000, break) ) } \\ Harry J. Smith, Sep 02 2009