OFFSET
1,9
COMMENTS
Marnell conjectures that a(n) > 0 for n > 10 after analyzing "many thousands of whole numbers". I find no exceptions below 100 million. - Charles R Greathouse IV, May 04 2010
REFERENCES
Geoffrey R. Marnell, "Ten Prime Conjectures", Journal of Recreational Mathematics 33:3 (2004-2005), pp. 193-196.
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(21) = #{7+2*7, 11+2*5, 17+2*2} = 3.
MATHEMATICA
Table[Count[Sort/@(PrimeOmega/@IntegerPartitions[n, {2}]), {1, 2}], {n, 110}] (* Harvey P. Dale, Mar 25 2018 *)
PROG
(PARI) list(lim)=my(p=primes(primepi(lim)), sp=select(n->bigomega(n)==2, vector(lim\1, i, i)), x=O('x^(lim\1+1))+'x); concat([0, 0, 0, 0, 0], Vec(sum(i=1, #p, x^p[i])*sum(i=1, #sp, x^sp[i]))) \\ Charles R Greathouse IV, Jun 14 2013
(Haskell)
a100949 n = sum $ map (a010051 . (n -)) $ takeWhile (< n) a001358_list
-- Reinhard Zumkeller, Jun 26 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, Nov 23 2004
STATUS
approved