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.

A212665 Numbers such that the greatest prime divisor is less than the sum of the other distinct prime divisors.

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%I A212665 #9 Sep 08 2019 10:05:25
%S A212665 105,210,315,385,420,429,462,525,630,715,735,770,840,858,910,924,945,
%T A212665 969,1001,1050,1105,1155,1260,1287,1309,1326,1365,1386,1430,1470,1540,
%U A212665 1547,1575,1615,1680,1716,1729,1820,1848,1870,1890,1925,1938,2002,2100,2145
%N A212665 Numbers such that the greatest prime divisor is less than the sum of the other distinct prime divisors.
%H A212665 Amiram Eldar, <a href="/A212665/b212665.txt">Table of n, a(n) for n = 1..10000</a>
%e A212665 105 is in the sequence because 105 = 3*5*7 and 7 < 5 + 3 = 8.
%p A212665 with(numtheory):for n from 2 to 3000 do:x:=factorset(n):m:=nops(x):s:=0: s:=sum( '
%p A212665 x[i] ', 'i'=1..m):q:=s-x[m]:if x[m] < q then printf(`%d, `,n):else fi:od:
%t A212665 aQ[n_] := Max[(p = FactorInteger[n][[;; , 1]])] < Total @ Most @ p; Select[Range[2200], aQ] (* _Amiram Eldar_, Sep 08 2019 *)
%K A212665 nonn
%O A212665 1,1
%A A212665 _Michel Lagneau_, May 23 2012