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%I #9 Sep 08 2022 08:46:19
%S 1,6,16,21,26,36,46,51,56,66,76,81,86,91,96,106,111,116,121,126,136,
%T 141,146,156,161,166,171,176,186,196,201,206,216,221,226,231,236,246,
%U 256,261,266,276,286,291,296,301,306,316,321,326,336,341,346,351,356,361,366,371
%N Nonprimes of the form 5*k + 1.
%C Subsequence of A018252.
%t DeleteCases[5 Range[0, 200] + 1, _?PrimeQ]
%o (Magma) [n: n in [1..400 by 5] | not IsPrime(n)];
%Y Cf. A016861, A030430, A091113, A091300, A291745, A291747.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Aug 31 2017