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%I #18 Sep 21 2015 20:08:44
%S 3,373,24307,1691682,127867801,10233538789,850896280551,
%T 72812857079241,6363727756215813,565232434009370012,
%U 50843507342073211151,4620323131256374760046,423405369424475640435621,39074878176445767411791424
%N Sum of distinct proper prime divisors of odd integers below 10^n.
%C Through 10^5 about 37.5% of total sums for all integers N comprise sums of odd N and the remaining 62.5% of even N.
%F a(n) = sum_{k=1,2,...,A093143(n)} A105221(2k-1). - _R. J. Mathar_, Jan 29 2008
%F a(n) = sum_{prime p, 3<=p<10^n} p*floor((10^n-p)/(2p)). - _Max Alekseyev_, Jan 30 2012
%e a(0)=3 because the only odd N <=10^1-1 having a prime factor is 9 and its factor is 3 and sum is 3.
%p A105221 := proc(n) local a,ifs,p; ifs := ifactors(n)[2] ; a := 0 ; for p in ifs do if op(1,p) <> 1 and op(1,p) <> n then a := a+op(1,p) ; fi ; od: RETURN(a) ; end: A136025 := proc(n) local a,k ; a := 0 ; for k from 5 to 10^n-1 by 2 do a := a+A105221(k) ; od: RETURN(a) ; end: for n from 1 do print(A136025(n)); od: # _R. J. Mathar_, Jan 29 2008
%Y Cf. A136021, A136024, A143851.
%K more,nonn
%O 1,1
%A _Enoch Haga_, Dec 12 2007
%E a(6) from _R. J. Mathar_, Jan 29 2008
%E a(7)-a(11) from _Max Alekseyev_, Jan 30 2012
%E a(12)-a(14) from _Hiroaki Yamanouchi_, Jul 06 2014
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