A168265 a(n) = A003557(A060735(n)).

1, 1, 2, 1, 2, 3, 4, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20

Offset: 1

Author

Matthew Vandermast, Nov 23 2009

Keywords

• easy
• nonn

Comments

A060735(n) belongs to A168264 if and only if a(n) belongs to A168267.

Looking at A060735 as an irregular triangle T(n,k) = k*A002110(n) with 1 <= k < prime(n+1), this sequence a(n) = k. - Michael De Vlieger, Jul 26 2016

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10123 (first 68 rows)

Crossrefs

Cf. A002110, A006093, A060735.

Programs

Mathematica

Table[Range[Prime[n] - 1], {n, 9}] // Flatten (* or, per title definition: *)
#/Times @@ (FactorInteger[#][[All, 1]]) & /@ Flatten@ Table[Range[Prime[n + 1] - 1] Apply[Times, Prime@ Range@ n], {n, 0, 8}] (* Michael De Vlieger, Jul 26 2016 *)

Formula

Integers 1 to A006093(1) inclusive, followed by integers 1 to A006093(2) inclusive, etc.

a(n) = A111701(A060735(n)).

T(n,k)=k for n >= 1 and 1 <= k < prime(n).