login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A324110 Numbers k such that A324108(k) != A324054(k-1). 6

%I #12 Jul 17 2021 11:23:52

%S 15,21,30,33,35,39,42,45,51,55,57,60,63,65,66,69,70,75,77,78,84,85,90,

%T 91,93,95,99,102,105,110,111,114,115,117,119,120,123,126,129,130,132,

%U 133,135,138,140,141,143,145,147,150,153,154,155,156,159,161,165,168,170,171,175,177,180,182,183,185,186,187,189,190,195,198,201

%N Numbers k such that A324108(k) != A324054(k-1).

%C This is a subsequence of A070537. The missing terms 1, 87, 174, 348, 696, 1392, 2091, ..., are at A324111.

%H Antti Karttunen, <a href="/A324110/b324110.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI)

%o A324054(n) = { my(p=2,mp=p*p,m=1); while(n, if(!(n%2), p=nextprime(1+p); mp = p*p, if(3==(n%4),mp *= p,m *= (mp-1)/(p-1))); n>>=1); (m); };

%o A324108(n) = { my(f=factor(n)); prod(i=1, #f~, A324054((f[i,1]^f[i,2])-1)); };

%o isA324110(n) = (A324054(n-1)!=A324108(n));

%o for(n=1,201,if(isA324110(n), print1(n,", ")))

%Y Cf. A070537, A324054, A324108, A324109 (complement), A324111.

%K nonn

%O 1,1

%A _Antti Karttunen_ and _David A. Corneth_, Feb 15 2019

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 02:13 EDT 2024. Contains 371264 sequences. (Running on oeis4.)