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 A222085 Sum of the least divisors of n whose LCM is equal to n. 6
 1, 3, 4, 7, 6, 6, 8, 15, 13, 8, 12, 10, 14, 10, 9, 31, 18, 21, 20, 12, 11, 14, 24, 24, 31, 16, 40, 14, 30, 11, 32, 63, 15, 20, 13, 25, 38, 22, 17, 20, 42, 19, 44, 18, 18, 26, 48, 52, 57, 43, 21, 20, 54, 66, 17, 22, 23, 32, 60, 15, 62, 34, 20, 127, 19, 23, 68 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Paolo P. Lava, Table of n, a(n) for n = 1..1000 EXAMPLE The divisors of 20 are 1, 2, 4, 5, 10, 20 while the least divisors of 20 whose LCM is equal to 20 are 1, 2, 4, 5. Then a(20) = 1+2+4+5 = 12. MAPLE with(numtheory); A222085:=proc(q) local a, b, c, j, n, v; print(1); for n from 2 to q do a:=ifactors(n)[2]; b:=nops(a); c:=0;   for j from 1 to b do if a[j][1]^a[j][2]>c then c:=a[j][1]^a[j][2]; fi; od;   a:=op(sort([op(divisors(n))])); b:=nops(divisors(n)); v:=0;   for j from 1 to b do v:=v+a[j]; if a[j]=c then break; fi; od; print(v); od; end: A222085(100000000); PROG (PARI) a(n)=my(s, L=1); fordiv(n, d, s+=d; L=lcm(L, d); if(L==n, return(s))) \\ Charles R Greathouse IV, Feb 14 2013 CROSSREFS Cf. A000005, A000961, A001358, A003418, A005179, A024619, A034444, A077610, A222084. Sequence in context: A105827 A230289 A023888 * A187793 A284326 A117553 Adjacent sequences:  A222082 A222083 A222084 * A222086 A222087 A222088 KEYWORD nonn AUTHOR Paolo P. Lava, Feb 11 2013 STATUS approved

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Last modified April 22 11:46 EDT 2019. Contains 322330 sequences. (Running on oeis4.)