cp's OEIS Frontend

A317126 Numbers of the form: (6*m + 1) * (12*m + 1) * Product_{i=1..k-2} (9 * 2^i * m + 1), where k >= 3, with the condition that each of the factors is prime and that m is divisible by 2^(k-4).

%I A317126 #21 Feb 16 2025 08:33:56
%S A317126 1729,63973,294409,56052361,118901521,172947529,216821881,228842209,
%T A317126 1299963601,2301745249,9624742921,11346205609,13079177569,21515221081,
%U A317126 27278026129,65700513721,71171308081,100264053529,168003672409,172018713961,173032371289,192739365541
%N A317126 Numbers of the form: (6*m + 1) * (12*m + 1) * Product_{i=1..k-2} (9 * 2^i * m + 1), where k >= 3, with the condition that each of the factors is prime and that m is divisible by 2^(k-4).
%C A317126 Also known as extended Chernick Carmichael numbers.
%C A317126 Each term of this sequence is the product of 3 or more distinct prime factors.
%H A317126 Daniel Suteu, <a href="/A317126/b317126.txt">Table of n, a(n) for n = 1..10081</a>
%H A317126 Jack Chernick, <a href="https://doi.org/10.1090/S0002-9904-1939-06953-X">On Fermat's simple theorem</a>, Bull. Amer. Math. Soc. 45:4 (1939), pp. 269-274.
%H A317126 Daniel Suteu, <a href="/A317126/a317126.pl.txt">Perl program</a>
%H A317126 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CarmichaelNumber.html">Carmichael Number</a>
%H A317126 <a href="/index/Ca#Carmichael">Index entries for sequences related to Carmichael numbers.</a>
%Y A317126 Cf. A033502.
%K A317126 nonn
%O A317126 1,1
%A A317126 _Daniel Suteu_, Jul 21 2018