cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A088824 Numbers n such that the sum of smallest prime factors of numbers from 1 to n is divisible by n.

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%I A088824 #12 Apr 27 2017 09:22:01
%S A088824 1,2,7,14,78,113,153,439,462,1215,2294,8363,11102,12302,36382,38370,
%T A088824 60398,199953,224090,421399,427131,1947938,2467022,2571633,62395623,
%U A088824 462027217,2140648015,6418011931,43074345625,52714450814,71229445182,90719472005,105685014433
%N A088824 Numbers n such that the sum of smallest prime factors of numbers from 1 to n is divisible by n.
%H A088824 Giovanni Resta, <a href="/A088824/b088824.txt">Table of n, a(n) for n = 1..38</a> (terms < 7.5*10^12)
%F A088824 Solutions to Mod[A088821[x], x]=0.
%t A088824 smp[n_] := If[n==1, 0, FactorInteger[n][[1, 1]]]; s = Accumulate @ Array[ smp, 10^5]; Select[Range[10^5], Mod[s[[#]], #] == 0 &] (* _Giovanni Resta_, Apr 27 2017 *)
%Y A088824 Cf. A088821-A088825.
%K A088824 nonn
%O A088824 1,2
%A A088824 _Labos Elemer_, Oct 22 2003
%E A088824 More terms from _Ray Chandler_, Oct 31 2003
%E A088824 a(27)-a(31) from _Donovan Johnson_, Jul 09 2010
%E A088824 a(32)-a(33) from _Giovanni Resta_, Apr 27 2017