login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A105089 Sum of the primes in ordered 3 X 3 prime squares. 1
100, 401, 763, 1163, 1601, 2053, 2501, 3017, 3517, 3997, 4479, 5105, 5571, 6045, 6639, 7217, 7741, 8331, 8927, 9417, 9949, 10613, 11201, 11711, 12467, 13063, 13559, 14159, 14653, 15311, 15937, 16661, 17253, 17959, 18531, 19093, 19813, 20461 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Partition the primes into consecutive and non-overlapping groups of nine primes and take the total of each group. - Harvey P. Dale, Sep 06 2018

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

An ordered 3 X 3 prime square is 9 consecutive primes arranged in a square of the form p(9n-8) p(9n-7) p(9n-6) p(9n-5) p(9n-4) p(9n-3) p(9n-2) p(9n-1) p(9n) n=1, 2, ...

EXAMPLE

The first 3 X 3 prime square

2 3 5

7 11 13

17 19 23

adds up to 100 the first entry in the table.

MATHEMATICA

With[{nn=40}, Total/@Partition[Prime[Range[9nn]], 9]] (* or *) Table[ Total[ Prime[Range[9i-8, 9i]]], {i, 40}] (* Harvey P. Dale, Sep 06 2018 *)

PROG

(PARI) sumsq3x3(n) = { local(x, j, s); forstep(x=0, n, 9, s=0; for(j=1, 9, s += prime(x+j); ); print1(s", ") ) }

CROSSREFS

Sequence in context: A250806 A250853 A017270 * A017510 A290654 A017642

Adjacent sequences:  A105086 A105087 A105088 * A105090 A105091 A105092

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Apr 07 2005

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 December 14 04:53 EST 2018. Contains 318090 sequences. (Running on oeis4.)