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%I #35 Nov 11 2020 02:43:14
%S 44,75,98,116,147,171,242,243,244,332,387,507,548,603,604,724,844,908,
%T 931,963,1075,1083,1251,1324,1412,1467,1556,1587,1675,1772,2523,2524,
%U 2636,2644,2763,3283,3356,3411,3508,3788,3987,4075,4203,4204,4418,4491,4804,4868,4923,4924
%N Numbers k such that k and k+1 both have 6 divisors.
%D David Wells, The Penguin Dictionary of Curious and Interesting Numbers, Penguin Books, 1986, entry 44, p. 103.
%H Amiram Eldar, <a href="/A049103/b049103.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Vincenzo Librandi)
%F a(n) = A049104(n) - 1. - _Zak Seidov_, Feb 11 2016
%t Flatten[Position[Partition[Table[DivisorSigma[0,n],{n,5000}],2,1],_?(# == {6,6}&)]] (* _Harvey P. Dale_, Apr 09 2012 *)
%o (PARI) isok(n) = (numdiv(n) == 6) && (numdiv(n+1) == 6); \\ _Michel Marcus_, Feb 11 2016
%Y Intersection of A005237 and A030515.
%Y Cf. A038400, A049104.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, _Felice Russo_, _Olivier Gérard_
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