A175944 1 appears once, n-th prime p appears p times.

1, 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

Offset

1,2

Comments

a(A014284(n)) = a(A175965(n)) = A018252(n). [Reinhard Zumkeller, Mar 18 2011]

This is how A063905 would have been reckoned at the beginning of the 20th century, taking the primes as given in A008578 instead of the way they are given in A000040. [Alonso del Arte, Sep 09 2011]

Links

Table of n, a(n) for n=1..75.

Formula

a(1)=1, a(n)=A063905(n-1) for n>1.

Mathematica

Join[{1}, Flatten[Table[Prime[n], {n, 8}, {Prime[n]}]]] (* Alonso del Arte, Sep 08 2011 based on Robert G. Wilson v's program for A002024 *)
Join[{1}, Flatten[Table[PadRight[{}, n, n], {n, Prime[Range[10]]}]]] (* Harvey P. Dale, May 16 2019 *)

Prog

(Haskell)
a175944 n = a175944_list !! (n-1)
a175944_list =
   concat $ zipWith ($) (map replicate a018252_list) a018252_list
-- Reinhard Zumkeller, Mar 18 2011

Crossrefs

Cf. A063905.

Cf. A005145.

Sequence in context: A131624 A165077 A165079 * A063905 A130312 A295629

Adjacent sequences: A175941 A175942 A175943 * A175945 A175946 A175947

Keyword

nonn,easy

Author

Juri-Stepan Gerasimov, Oct 27 2010

Status

approved