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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A080854 Numbers which can be expressed as the sum of two distinct primes in exactly five ways. 4
48, 54, 64, 70, 76, 104, 106, 118, 124, 134, 136, 146, 148, 164, 166, 188 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

54 is a term as 54 = 31 + 23 = 37 + 17 = 41 + 13 = 43 + 11 = 47 + 7 are only the five ways to express 54 as a sum of two distinct primes.

MAPLE

P:=proc(q, w) local a, k, n;

for n from 1 to q do a:=0; for k from 1 to trunc(n/2) do

if isprime(k) and isprime(n-k) and n<>2*k then a:=a+1; fi; od;

if a=w then print(n); fi; od; end: P(200, 5); # Paolo P. Lava, May 21 2014

CROSSREFS

Cf. A077914 (2 ways), A077969 (3 ways), A078299 (4 ways), A080862 (6 ways).

Sequence in context: A258694 A328738 A067191 * A255267 A259037 A231469

Adjacent sequences:  A080851 A080852 A080853 * A080855 A080856 A080857

KEYWORD

nonn

AUTHOR

Shyam Sunder Gupta, Mar 29 2003

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 January 23 07:07 EST 2020. Contains 331168 sequences. (Running on oeis4.)