cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A345946 Prime powers k that have such a proper divisor d for which A002034(d) = A002034(k).

Original entry on oeis.org

8, 64, 81, 128, 1024, 6561, 8192, 15625, 16384, 32768, 262144, 531441, 1594323, 2097152, 4194304, 5764801, 33554432, 129140163, 244140625, 268435456, 536870912, 1073741824, 2147483648, 10460353203, 17179869184, 137438953472, 274877906944, 847288609443, 2199023255552
Offset: 1

Views

Author

Antti Karttunen, Jul 04 2021

Keywords

Comments

Numbers k such that A345950(k) = 0 (or equivalently, A345935(k) > 1), and A010055(k) = 1.

Examples

			8 = 2^3 is present because A002034(8) = 4 = A002034(4).
		

Crossrefs

Intersection of A000961 and A345945.

Programs

  • PARI
    A002034(n) = if(1==n,n,my(s=factor(n)[, 1], k=s[#s], f=Mod(k!, n)); while(f, f*=k++); (k)); \\ After code in A002034.
    A345950(n) = { my(x=A002034(n)); fordiv(n,d,if(A002034(d)==x,return(d==n))); };
    isA345946(n) = (!isprime(n) && isprimepower(n) && !A345950(n));

Extensions

More terms from Jinyuan Wang, Jul 07 2021