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 A108422 Greatest number of ones that can be used to write in binary representation 2*n as sum of two primes. 3
 2, 4, 4, 5, 5, 6, 5, 6, 6, 6, 6, 6, 6, 7, 6, 7, 7, 8, 7, 8, 8, 8, 7, 8, 8, 9, 7, 8, 9, 10, 7, 8, 8, 9, 8, 9, 9, 10, 8, 9, 9, 8, 9, 10, 10, 10, 8, 8, 9, 9, 9, 10, 10, 10, 9, 9, 8, 10, 10, 10, 8, 10, 8, 9, 9, 10, 9, 10, 10, 9, 9, 10, 9, 11, 9, 10, 11, 12, 9, 10, 10, 10, 10, 11, 9, 12, 8, 9, 11, 10, 8, 12 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS a(n) = Max{A000120(p)+A000120(q): p,q prime and p+q=2*n); a(n) = A108423(n) + A108421(n). LINKS Robert Israel, Table of n, a(n) for n = 2..10000 MAPLE N:= 200: # to get a(2)..a(N) Primes:= select(isprime, [seq(i, i=3..2*N-3, 2)]): Ones:= map(t -> convert(convert(t, base, 2), `+`), Primes): V:= Vector(N): V[2]:= 2: for i from 1 to nops(Primes) do p:= Primes[i]; for j from 1 to i do k:= (p+Primes[j])/2; if k > N then break fi; t:= Ones[i]+Ones[j]; if t > V[k] then V[k]:= t fi od od: convert(V[2..N], list); # Robert Israel, Mar 26 2018 CROSSREFS Cf. A004676, A005843, A007088, A108421. Sequence in context: A036443 A036437 A053306 * A276523 A244320 A084616 Adjacent sequences: A108419 A108420 A108421 * A108423 A108424 A108425 KEYWORD nonn,base AUTHOR Reinhard Zumkeller, Jun 03 2005 STATUS approved

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Last modified November 26 14:22 EST 2022. Contains 358362 sequences. (Running on oeis4.)