%I A001747
%S A001747 2,4,6,10,14,22,26,34,38,46,58,62,74,82,86,94,106,118,122,
%T A001747 134,142,146,158,166,178,194,202,206,214,218,226,254,262,
%U A001747 274,278,298,302,314,326,334,346,358,362,382,386,394,398,422,446,454,458,
               466,478,482,502,514,526,538,542,554,562,566,586,614,622,626,634
%N A001747 2 together with primes multiplied by 2.
%C A001747 When supplemented with 8, may be considered the "even primes", since 
               these are the even numbers n = 2k which are divisible just by 1, 
               2, k and 2k - Louis Zuckerman (louis(AT)trapezoid.com), Sep 12 2000.
%C A001747 Sequence gives solutions of sigma(n)-phi(n)=n+tau(n) where tau(n) is 
               the number of divisors of n
%C A001747 Numbers n such that sigma(n)=3*(n-phi(n))
%C A001747 Except for 2, orders of non-cyclic groups k (in A060679(n)) such that 
               x^k==1 (mod k) has only 1 solution 2<=x<=k - Benoit Cloitre (benoit7848c(AT)orange.fr), 
               May 10 2002
%C A001747 Except for initial terms, this sequence = A073582 = A074845 = A077017. 
               Starting with the term 10, they are identical. - Robert G. Wilson 
               v, Jun 15 2004
%C A001747 a(n) = A116366(n-2,n-2) for n>2. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Feb 06 2006
%C A001747 A006093(n) = A143201(a(n+1)) for n>1. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Aug 12 2008]
%H A001747 T. D. Noe, <a href="b001747.txt">Table of n, a(n) for n=1..1000</a>
%F A001747 n such that A092673(n)=2 - Jon Perry (perry(AT)globalnet.co.uk), Mar 
               02 2004
%Y A001747 Cf. A060679, A009530, A098764.
%Y A001747 a(n) = A001043(n) - A001223(n+1), except for initial term.
%Y A001747 {2} UNION {A100484}.
%Y A001747 Sequence in context: A000065 A023499 A103445 this_sequence A048670 A077625 
               A027383
%Y A001747 Adjacent sequences: A001744 A001745 A001746 this_sequence A001748 A001749 
               A001750
%K A001747 nonn,easy,nice
%O A001747 1,1
%A A001747 N. J. A. Sloane (njas(AT)research.att.com).