A364716 - OEIS

%I #9 Aug 04 2023 08:16:01

%S 61,193,277,361,397,421,457,613,757,997,1213,1237,1453,1657,1867,1873,

%T 1933,2137,2347,2593,2797,2917,3013,3183,3217,3361,3427,3481,3517,

%U 3697,3721,3805,4057,4083,4177,4261,4603,4621,4717,4771,4813,4957,5029,5041,5101,5107,5223

%N Numbers k such that d(k) < d(k+1) < d(k+2) < d(k+3), where d(n) is the number of divisors of n.

%o (PARI) isok(n) = numdiv(n)<numdiv(n+1) && numdiv(n+1)<numdiv(n+2) && numdiv(n+2)<numdiv(n+3);

%Y Cf. A000005, A075028, A364662, A364719.

%Y Cf. A074775, A364715, A364717.

%K nonn

%O 1,1

%A _Seiichi Manyama_, Aug 04 2023