The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A095723 0+1+Prime power perfect numbers: if n=Product p_i^r_i then 01PPsigma(n)= Product {Sum p_i^r_i, 0<=s_i<=r_i, s_i is 0 or one or prime} 01PPsigma(n)=2*n. 1

%I

%S 6,28,4512,65520,694400

%N 0+1+Prime power perfect numbers: if n=Product p_i^r_i then 01PPsigma(n)= Product {Sum p_i^r_i, 0<=s_i<=r_i, s_i is 0 or one or prime} 01PPsigma(n)=2*n.

%C Factorizations : 2*3, 2^2*7, 2^5*3*47, 2^4*3^2*5*7*13, 2^7*5^2*7*31

%C No other terms < 3000000000. - _Jud McCranie_, Jul 16 2004

%e 01PPsigma(2^5*3^3)=(1+2+2^2+2^3+2^5)*(1+3+3^2+3^3)=1880

%e All exponents of the terms are 0 or 1 or prime.

%Y Cf. A096290, A095724.

%K nonn

%O 1,1

%A _Yasutoshi Kohmoto_, Jul 08 2004

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

Last modified September 20 17:42 EDT 2021. Contains 347588 sequences. (Running on oeis4.)