A358988 Oblong numbers which are products of four distinct primes.

210, 462, 870, 930, 1122, 1190, 1482, 1722, 1806, 3306, 4422, 4970, 6162, 7310, 7482, 8742, 8930, 10302, 10506, 11990, 12882, 14042, 15006, 17030, 17822, 18906, 19182, 20022, 20306, 21170, 25122, 30102, 31506, 32942, 36290, 40602, 41006, 42230, 45582, 46010, 47306

Offset: 1

Author

Massimo Kofler, Dec 10 2022

Keywords

• nonn

Examples

			210 = 14*15 = 2*3*5*7.
1122 = 33*34 = 2*3*11*17.
10302 = 101*102 = 2*3*17*101.
20306 = 142*143 = 2*11*13*71.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Intersection of A002378 and A046386.

Programs

Mathematica

Select[(#*(# + 1)) & /@ Range[220], FactorInteger[#][[;; , 2]] == {1, 1, 1, 1} &] (* Amiram Eldar, Dec 10 2022 *)
Select[Times@@@Partition[Range[400],2,1],PrimeNu[#]==PrimeOmega[#]==4&] (* Harvey P. Dale, Jul 08 2025 *)