A359127 Oblong numbers which are products of six distinct primes.

43890, 53130, 81510, 108570, 152490, 184470, 188790, 260610, 297570, 371490, 416670, 475410, 509082, 549822, 593670, 637602, 648830, 756030, 757770, 814506, 932190, 939930, 973182, 1003002, 1045506, 1135290, 1178310, 1222130, 1233210, 1257762, 1278030, 1332870, 1414910, 1417290, 1484742

Offset

1,1

Links

Table of n, a(n) for n=1..35.

Example

43890 = 209*210 = 2*3*5*7*11*19
53130 = 230*231 = 2*3*5*7*11*23
81510 = 285*286 = 2*3*5*11*13*19
108570 = 329*330 = 2*3*5*7*11*47

Maple

R:= NULL: count:= 0:
for n from 1 while count < 100 do
  x:= n*(n+1);
  F:= ifactors(x)[2];
  if nops(F) = 6 and max(map(t -> t[2], F))=1 then
     R:= R, x; count:= count+1;
  fi
od:
R; # Robert Israel, Dec 26 2022

Mathematica

Select[(#*(# + 1)) & /@ Range[1250], FactorInteger[#][[;; , 2]] == {1, 1, 1, 1, 1, 1} &] (* Amiram Eldar, Dec 26 2022 *)

Crossrefs

Intersection of A002378 and A067885.

Cf. A359304.

Sequence in context: A043303 A233790 A378097 * A223457 A338541 A190377

Adjacent sequences: A359124 A359125 A359126 * A359128 A359129 A359130

Keyword

nonn

Author

Massimo Kofler, Dec 26 2022

Status

approved