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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A130503 a(n) = denominator of the sum of reciprocals of those positive integers which are <= n and are not among the first (n-1) terms of A130502. 2

%I

%S 1,2,6,12,12,4,28,56,504,2520,27720,27720,27720,27720,5544,11088,

%T 188496,62832,1193808,5969040,1989680,1989680,45762640,137287920,

%U 686439600,8923714800,80313433200,80313433200,2329089562800,2329089562800

%N a(n) = denominator of the sum of reciprocals of those positive integers which are <= n and are not among the first (n-1) terms of A130502.

%H Diana Mecum, <a href="/A130503/b130503.txt">Table of n, a(n) for n = 1..200</a>

%e The positive integers which are <= 9 and are missing from the first 8 terms of the (numerator) sequence A130502 are 2,3,4,6,7,8,9. So a(9) is the denominator of (1/2 +1/3 +1/4 +1/6 +1/7 +1/8 + 1/9 = 821/504).

%Y Cf. A130502.

%K frac,nonn

%O 1,2

%A _Leroy Quet_, May 31 2007

%E More terms from _Diana L. Mecum_, Jun 14 2007

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.

Last modified July 28 15:51 EDT 2021. Contains 346335 sequences. (Running on oeis4.)