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%I #10 Nov 12 2017 08:19:49
%S 1,2,6,10,14,18,30,34,38,46,50,58,66,78,86,90,94,98,106,118,130,134,
%T 150,154,170,174,186,190,198,206,214,218,226,234,254,258,266,270,274,
%U 286,294,310,314,318,326,338,350,354,366,370,394,398,406,410,426,430
%N Numbers k such that A000005(k) = A000005(A000326(k)).
%C Numbers k such that the number of divisors of k is equal to the number of divisors of the pentagonal number k*(3*k-1)/2.
%H Colin Barker, <a href="/A281703/b281703.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Range[500],DivisorSigma[0,#]==DivisorSigma[0,(#(3#-1))/2]&] (* _Harvey P. Dale_, Nov 12 2017 *)
%o (PARI) select(k->numdiv(k)==numdiv(k*(3*k-1)/2), vector(500, k, k))
%Y Cf. A000005, A000326, A087370, A281702.
%K nonn
%O 1,2
%A _Colin Barker_, Jan 28 2017
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