cp's OEIS Frontend

A359127 Oblong numbers which are products of six distinct primes.

%I A359127 #21 Jan 14 2023 19:54:26
%S A359127 43890,53130,81510,108570,152490,184470,188790,260610,297570,371490,
%T A359127 416670,475410,509082,549822,593670,637602,648830,756030,757770,
%U A359127 814506,932190,939930,973182,1003002,1045506,1135290,1178310,1222130,1233210,1257762,1278030,1332870,1414910,1417290,1484742
%N A359127 Oblong numbers which are products of six distinct primes.
%e A359127 43890 = 209*210 = 2*3*5*7*11*19
%e A359127 53130 = 230*231 = 2*3*5*7*11*23
%e A359127 81510 = 285*286 = 2*3*5*11*13*19
%e A359127 108570 = 329*330 = 2*3*5*7*11*47
%p A359127 R:= NULL: count:= 0:
%p A359127 for n from 1 while count < 100 do
%p A359127   x:= n*(n+1);
%p A359127   F:= ifactors(x)[2];
%p A359127   if nops(F) = 6 and max(map(t -> t[2],F))=1 then
%p A359127      R:= R, x; count:= count+1;
%p A359127   fi
%p A359127 od:
%p A359127 R; # _Robert Israel_, Dec 26 2022
%t A359127 Select[(#*(# + 1)) & /@ Range[1250], FactorInteger[#][[;; , 2]] == {1, 1, 1, 1, 1, 1} &] (* _Amiram Eldar_, Dec 26 2022 *)
%Y A359127 Intersection of A002378 and A067885.
%Y A359127 Cf. A359304.
%K A359127 nonn
%O A359127 1,1
%A A359127 _Massimo Kofler_, Dec 26 2022