# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a082895 Showing 1-1 of 1 %I A082895 #15 May 27 2019 01:55:46 %S A082895 1,4,3,8,5,12,7,16,9,20,11,24,13,28,30,32,17,36,19,40,42,44,23,72,25, %T A082895 52,27,56,29,60,31,64,33,68,35,108,37,76,39,80,41,84,43,88,90,92,47, %U A082895 144,49,100,51,104,53,108,55,112,57,116,59,180,61,124,126,128,65,132,67,136,69 %N A082895 Closest number to sigma(n) = A000203(n) which is divisible by n. %C A082895 In the case of a tie, we round up. - _Robert Israel_, May 26 2019 %H A082895 Robert Israel, Table of n, a(n) for n = 1..10000 %F A082895 a(n) = n*floor((floor(n/2)+sigma(n))/n). %e A082895 n=100: sigma[100]=217 is between 100=1.100 and 200=2.100 %e A082895 200 is closer to 217, so a[100]=200; %p A082895 f:= proc(n) uses numtheory; n*floor((floor(n/2)+sigma(n))/n) end proc: %p A082895 map(f, [$1..100]); # _Robert Israel_, May 26 2019 %t A082895 Table[n*Floor[(Floor[n/2]+DivisorSigma[1, n])/n], {n, 1, 100}] %o A082895 (PARI) a(n)=sigma(n)\/n*n \\ _Charles R Greathouse IV_, Feb 15 2013 %Y A082895 Cf. A082893-A082900, A000203. %K A082895 nonn,look %O A082895 1,2 %A A082895 _Labos Elemer_, Apr 22 2003 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE