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A261153 a(n) is the maximum number of distinct primes whose sum is n. 0
0, 0, 1, 1, 0, 2, 0, 2, 2, 2, 3, 1, 3, 2, 3, 3, 3, 4, 3, 3, 3, 4, 3, 4, 3, 4, 4, 4, 5, 4, 5, 4, 4, 4, 5, 4, 5, 4, 5, 5, 5, 6, 5, 5, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6, 5, 6, 6, 6, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

a(A007504(k)) = k.

a(n) < k when n < A007504(k).

Let pi(j) be the j-th prime. Then a(A007504(k) - pi(j)) = k-1, j<=k. For example, k=5: A007504(5) = 28, pi(5)=11. So a(n)=4, n = {26,25,23,21,17}.

Similarly, a(A007504(k) + pi(j)) = k+1, where j>k and A007504(k) + pi(j) < A007504(k+2). For example, k=8: A007504(8) = 77, A007504(10) = 129 and pi(8)=19. Therefore, a(n)=9, n = {100,106,108,114,118,120,124}.

LINKS

Table of n, a(n) for n=0..58.

EXAMPLE

a(26)=4 because 3+5+7+11 = 26. Note that some terms may be expressed in multiple ways. For example, a(47)=6: 2+3+5+7+11+19 and 2+3+5+7+13+17 = 47.

CROSSREFS

Cf. A000040 (prime numbers), A007504.

Sequence in context: A278248 A036461 A244478 * A199123 A325589 A291308

Adjacent sequences:  A261150 A261151 A261152 * A261154 A261155 A261156

KEYWORD

nonn,easy

AUTHOR

Bob Selcoe, Aug 10 2015

STATUS

approved

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Last modified May 22 19:19 EDT 2019. Contains 323481 sequences. (Running on oeis4.)