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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A174847 Number m of ways of representing 2n+1 as a sum of three primes such that all 3m primes are distinct. 0
0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 3, 3, 3, 4, 4, 4, 4, 5, 4, 4, 4, 4, 5, 4, 5, 5, 5, 5, 5, 4, 5, 6, 5, 6, 6, 6, 6, 6, 6, 6, 7, 6, 6, 6, 6, 7, 6, 7, 7, 7, 7, 7, 7, 6, 7, 8, 7, 7, 7, 7, 8, 8, 7, 8, 8, 8, 9, 8, 8, 9, 8, 8, 8, 8, 9, 9, 8, 9, 9, 9, 8, 9, 9, 9, 9, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,15

COMMENTS

a(n) <= A102605(n) (Number of ways of writing 2n+1 as p+q+r where p,q,r are distinct primes).

Minimal numbers with n representation as sum of triple of primes such that all 3n primes are distinct are:

15,29,49,71,91,119,137,167,189,227,

255,273,317,345,375,369,435,483,495,535,

567,597,641,651,699,731,755,791,821,867,921,975.

LINKS

Table of n, a(n) for n=0..113.

EXAMPLE

First number with m=1 is 15=3+5+7; for m=2,3,4 we have:

m=2: 29=3+7+19=5+11+13;  m=3: 49=3+5+41=5+7+37=13+17+19; m=4: 71=3+7+61=5+13+53=7+11+53=13+17+41.

CROSSREFS

Cf. A102605.

Sequence in context: A055098 A297035 A055178 * A215887 A159451 A103159

Adjacent sequences:  A174844 A174845 A174846 * A174848 A174849 A174850

KEYWORD

nonn

AUTHOR

Zak Seidov, Dec 01 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 23 03:26 EDT 2019. Contains 322380 sequences. (Running on oeis4.)