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%I #17 Jun 04 2022 04:30:00
%S 2,3,12,30,42,60,68,102,108,112,123,128,162,168,198,200,212,213,252,
%T 294,302,312,318,333,336,338,372,387,447,448,450,462,498,502,522,542,
%U 578,592,598,600,606,612,648,672,678,708,717,752,762,795,808,810,812
%N Numbers k such that k^2-1 and k^2+1 have the same number of positive divisors.
%H Amiram Eldar, <a href="/A069062/b069062.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[1000], DivisorSigma[0, #^2 - 1] == DivisorSigma[0, #^2 + 1] &] (* _Amiram Eldar_, Jun 04 2022 *)
%o (PARI) isok(n) = numdiv(n^2-1) == numdiv(n^2+1); \\ _Michel Marcus_, Nov 24 2013
%Y Cf. A000005, A002522, A005563, A193432, A347191.
%K easy,nonn
%O 1,1
%A _Benoit Cloitre_, Apr 04 2002
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