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!)
A152985 Sum of proper divisors minus the number of proper divisors of the square A000290(n). 1
0, 1, 2, 11, 4, 47, 6, 57, 36, 109, 10, 245, 12, 195, 170, 247, 16, 509, 18, 547, 292, 439, 22, 1055, 152, 597, 358, 969, 28, 1895, 30, 1013, 632, 985, 534, 2431, 36, 1215, 850, 2317, 40, 3397, 42, 2173, 1712, 1747, 46, 4313, 396, 2953, 1382, 2955, 52, 4715, 1090, 4083 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

B. D. Swan, Table of n, a(n) for n=1,...,50000

FORMULA

a(n) = A001065(A000290(n)) - A032741(A000290(n)) = A152770(A000290(n)).

PROG

(PARI) a(n) = sigma(n^2) - n^2 - (numdiv(n^2) - 1); \\ Michel Marcus, Jan 28 2014

CROSSREFS

Cf. A000005, A000203, A000290, A001065, A032741, A152770.

Sequence in context: A082264 A070532 A038217 * A257112 A077272 A009301

Adjacent sequences:  A152982 A152983 A152984 * A152986 A152987 A152988

KEYWORD

nonn,look

AUTHOR

Omar E. Pol, Dec 21 2008

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 May 28 21:37 EDT 2020. Contains 334690 sequences. (Running on oeis4.)