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A080862 Numbers which can be expressed as the sum of two distinct primes in exactly six ways. 4
60, 66, 72, 100, 110, 116, 172, 178, 182, 194, 206, 212, 218, 226, 248, 278, 326, 332, 398 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

66 is a term as 66 = 37 + 29 = 43 + 23 = 47 + 17 = 53 + 13 = 59 + 7 = 61 + 5 are only the six ways to express 66 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(400, 6); # Paolo P. Lava, May 21 2014

CROSSREFS

Cf. A077914 (2 ways), A077969 (3 ways), A078299 (4 ways), A080854 (5 ways).

Sequence in context: A138690 A118155 A066722 * A239415 A106130 A216828

Adjacent sequences:  A080859 A080860 A080861 * A080863 A080864 A080865

KEYWORD

nonn

AUTHOR

Shyam Sunder Gupta, Mar 29 2003

STATUS

approved

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Last modified January 21 13:55 EST 2020. Contains 331113 sequences. (Running on oeis4.)