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!)
A174226 Partial sums of A034897. 0
6, 27, 55, 356, 681, 1177, 1874, 3207, 5116, 7157, 9290, 13191, 21319, 32012, 48525, 68046, 92647, 119624, 170925, 267286, 397439, 557280, 720481, 897142, 1111415, 1361736, 1637569, 1933910, 2240091, 2629684, 3116561, 3612090, 4154503 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Partial sums of hyperperfect numbers. The subsequence of prime values in this partial sum begins: 21319, 92647, 720481.

LINKS

Table of n, a(n) for n=1..33.

FORMULA

a(n) = SUM[i=1..n] A034897(i) = SUM[i=1..n] {m such that k*sigma(m) = (k+1)*m + k - 1 for some positive integer k, and sigma being the divisor function A000005; noting that k=1 gives perfect numbers}.

EXAMPLE

a(x) = 6 + 21 + 28 + 301 + 325 + 496 + 697 + 1333 + 1909 + 2041 + 2133 + 3901 + 8128 + 10693 + 16513 + 19521 + 24601 = 92647 is prime.

CROSSREFS

Cf. A034897, A034898, A007592, A019279.

Sequence in context: A183603 A067876 A309337 * A100784 A174974 A273578

Adjacent sequences:  A174223 A174224 A174225 * A174227 A174228 A174229

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Mar 12 2010

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 April 13 06:02 EDT 2021. Contains 342935 sequences. (Running on oeis4.)