OFFSET
1,5
COMMENTS
a(n/2)=0 for the n in A007534. The logarithmic plot of this sequence seems very regular after 200000 terms.
LINKS
T. D. Noe, Table of n, a(n) for n=1..10000
James Grime and Brady Haran, Goldbach Conjecture (but with TWIN PRIMES), Numberphile video (2024)
T. D. Noe, Logarithmic plot of 10^6 terms
FORMULA
EXAMPLE
a(11)=3 because 22 = 3+19 = 5+17 = 11+11.
MATHEMATICA
nn=1000; tw=Select[Prime[Range[PrimePi[nn]]], PrimeQ[ #+2]&]; tw=Union[tw, tw+2]; tc=Table[0, {nn}]; tc[[tw]]=1; Table[cnt=0; k=1; While[tw[[k]]<=n/2, cnt=cnt+tc[[n-tw[[k]]]]; k++ ]; cnt, {n, 2, nn, 2}]
PROG
(Haskell)
a129363 n = sum $ map (a164292 . (2*n -)) $ takeWhile (<= n) a001097_list
-- Reinhard Zumkeller, Feb 03 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Apr 11 2007
EXTENSIONS
Comment converted to crossref by Klaus Brockhaus, Oct 27 2010
STATUS
approved