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%I
%S 3,13,13,491,1516,12721,12721,109453,1473257,120797465,624141002,
%T 4044619541,136797949237,315400191511,1285600699441
%N Smallest k such that sopf(k) >= sopf(k+1) >= ... >= sopf(k+n), where sopf = A008472.
%C Here sopf(k) is the sum of the distinct primes dividing k (A008472).
%C a(16) > 10^13.
%e sopf(13) = 13, sopf(14) = 9, sopf(15) = 8, sopf(16) = 2. This is the first run of 4 nonincreasing values, so a(4) = 13.
%t sopf[n_] := If[n == 1, 0, Total[First /@ FactorInteger@n]]; s = Array[ sopf, 120000]; Table[ SelectFirst[ Range[ Length@s - n], Sort[t = Take[s, {#, # + n}]] == Reverse[t] &], {n, 8}]
%Y Cf A008472, A189882.
%K nonn,more
%O 1,1
%A _Giovanni Resta_, May 04 2017
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