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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A325823 Sum of unitary proper divisors of A228058(n): a(n) = A034460(A228058(n)). 4
15, 23, 27, 55, 39, 39, 47, 51, 87, 43, 63, 71, 127, 63, 83, 55, 99, 67, 175, 107, 111, 63, 119, 123, 67, 95, 147, 79, 159, 99, 167, 79, 295, 87, 183, 135, 191, 203, 207, 367, 87, 99, 91, 139, 239, 243, 251, 795, 115, 267, 111, 279, 123, 287, 127, 291, 103, 303, 535, 135, 323, 139, 327, 187, 715, 111, 119, 347, 359, 363, 123, 383 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..25000

FORMULA

a(n) = A034460(A228058(n)).

a(n) = A325824(n) - A325379(n).

PROG

(PARI)

up_to = 10000;

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));

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); };

v228058 = A228058list(up_to);

A228058(n) = v228058[n]; \\ Antti Karttunen, May 23 2019

A034448(n) = { my(f=factorint(n)); prod(k=1, #f~, 1+(f[k, 1]^f[k, 2])); }; \\ After code in A034448

A034460(n) = (A034448(n) - n);

A325823(n) = A034460(A228058(n));

CROSSREFS

Cf. A034448, A034460, A228058, A325379, A325824.

Cf. also A325319, A325320.

Sequence in context: A166665 A317295 A014312 * A129387 A341170 A171167

Adjacent sequences:  A325820 A325821 A325822 * A325824 A325825 A325826

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 23 2019

STATUS

approved

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 29 09:31 EDT 2021. Contains 346344 sequences. (Running on oeis4.)