cp's OEIS Frontend

A325824 a(n) = A325814(A228058(n)).

%I A325824 #9 May 28 2019 19:35:52
%S A325824 27,75,99,203,171,255,219,243,171,335,315,363,539,539,435,575,531,707,
%T A325824 767,579,603,735,651,675,815,507,819,1055,891,675,939,1211,1343,1215,
%U A325824 1035,1419,1083,1155,1179,1691,1547,1455,1715,1859,1371,1395,1443,759,1775,1539,1179,1611,1935,1659,2015,1683,2219,1755,2507,2175,1875,2255
%N A325824 a(n) = A325814(A228058(n)).
%C A325824 First negative term occurs as a(16307) = -210973, with A228058(16307) = 1289925. The next negative terms occurs as a(20807) = -242901, with A228058(20807) = 1686825.
%H A325824 Antti Karttunen, <a href="/A325824/b325824.txt">Table of n, a(n) for n = 1..25000</a>
%F A325824 a(n) = A325814(A228058(n)).
%F A325824 a(n) = A325379(n) + A325823(n).
%o A325824 (PARI)
%o A325824 up_to = 10000;
%o A325824 isA228058(n) = if(!(n%2)||(omega(n)<2),0,my(f=factor(n),y=0); for(i=1,#f~,if(1==(f[i,2]%4), if((1==y)||(1!=(f[i,1]%4)),return(0),y=1), if(f[i,2]%2, return(0)))); (y));
%o A325824 A228058list(up_to) = { my(v=vector(up_to), k=0, n=0); while(k<up_to, n++; if(isA228058(n), k++; v[k] = n)); (v); };
%o A325824 v228058 = A228058list(up_to);
%o A325824 A228058(n) = v228058[n]; \\ _Antti Karttunen_, May 23 2019
%o A325824 A034448(n) = { my(f=factorint(n)); prod(k=1, #f~, 1+(f[k, 1]^f[k, 2])); }; \\ After code in A034448
%o A325824 A048146(n) = (sigma(n)-A034448(n));
%o A325824 A325814(n) = (n-A048146(n));
%o A325824 A325824(n) = A325814(A228058(n));
%Y A325824 Cf. A228058, A325379, A325814, A325822, A325823.
%Y A325824 Cf. also A325320.
%K A325824 sign
%O A325824 1,1
%A A325824 _Antti Karttunen_, May 23 2019