This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A057643 Least common multiple of all (k+1)'s, where the k's are the positive divisors of n. 8

%I

%S 2,6,4,30,6,84,8,90,20,66,12,5460,14,120,48,1530,18,7980,20,2310,88,

%T 276,24,81900,78,378,140,3480,30,114576,32,16830,204,630,72,3838380,

%U 38,780,280,284130,42,397320,44,4140,5520,1128,48,9746100,200,14586,468

%N Least common multiple of all (k+1)'s, where the k's are the positive divisors of n.

%C a(n) is a divisor of A020696(n). - _Ivan Neretin_, May 27 2015

%H Carl R. White, <a href="/A057643/b057643.txt">Table of n, a(n) for n = 1..10000</a>

%e Since the positive divisors of 6 are 1, 2, 3 and 6, a(6) = LCM(1+1,2+1,3+1,6+1) = LCM(2,3,4,7) = 84.

%p f:= n -> ilcm(op(map(`+`,numtheory:-divisors(n),1)));

%p seq(f(n),n=1..100); # _Robert Israel_, Jul 24 2014

%t a057643[n_Integer] := Apply[LCM, Map[# + 1 &, Divisors[n]]]; Table[a057643[n], {n, 10000}] (* _Michael De Vlieger_, Jul 19 2014 *)

%o (PARI) a(n)=lcm(apply(d->d+1,divisors(n))) \\ _Charles R Greathouse IV_, Feb 14 2013

%Y Cf. A119250.

%Y Cf. A020696 (product instead of LCM).

%K nonn

%O 1,1

%A _Leroy Quet_, Oct 11 2000

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 April 19 16:18 EDT 2019. Contains 322282 sequences. (Running on oeis4.)