A360129 - OEIS

%I #6 Feb 21 2023 07:35:14

%S 572,1144,1292,1768,2288,2584,2590,3496,3596,4030,4576,4930,6292,6992,

%T 7052,7192,7436,8050,8170,8246,9044,9152,9212,9430,9724,9758,10868,

%U 11408,12136,12584,12950,13984,14104,14212,14384,14396,14872,15370,16168,16492,16588,16796,17066,17168,17732,18130,18304

%N Numbers k such that A360119(k) > 1, but which have no divisors d > 1 such that d+1 is also a divisor.

%F {k | A088722(k) = 0 and A360119(k) > 1}.

%o (PARI)

%o A360119(n) = { my(d=divisors(n), erot=vecsort(vector(#d-1, k, d[k+1] - d[k])), s=#d); for(i=1,#erot,if(n%erot[i], s--, if(1==i || erot[i]!=erot[i-1], s--))); (s); };

%o A360128(n) = !sumdiv(n,d,(d>1)&&!(n%(d+1)));

%o isA360129(n) = (A360128(n)&&(A360119(n)>1));

%Y Subsequence of A088725.

%Y Cf. A088722, A360119, A360128.

%K nonn

%O 1,1

%A _Antti Karttunen_, Feb 20 2023