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A183168 Number of partitions of n^2 into three distinct primes. 3
0, 0, 0, 1, 2, 3, 8, 2, 17, 3, 41, 7, 61, 6, 69, 8, 152, 11, 216, 6, 204, 10, 383, 16, 464, 14, 447, 14, 791, 18, 978, 18, 822, 18, 1302, 25, 1684, 27, 1387, 24, 2347, 28, 2726, 27, 2012, 34, 3620, 31, 4005, 32, 3218, 44, 5274, 44, 5461, 36, 4538, 43, 7429 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

For n>3, odd n have (many) more partitions than even n.

LINKS

Zak Seidov, Table of n, a(n) for n = 1..200

EXAMPLE

a(4)=1 because 16=2+3+11,

a(6)=3 because 36=2+3+31=2+5+29=2+11+13.

PROG

(PARI) a(n)=my(s); n*=n; forprime(p=n\3, n-4, forprime(q=(n-p)\2+1, min(n-p, p-1), if(isprime(n-p-q), s++))); s \\ Charles R Greathouse IV, Aug 27 2012

(Haskell)

a183168 n = z (drop (fromInteger (mod n 2)) a000040_list) (n ^ 2) 3 where

   z _      m 1 = if m <= 0 then 0 else a010051 m

   z (p:ps) m c = if m <= 2*p then 0 else z ps (m - p) (c - 1) + z ps m c

-- Reinhard Zumkeller, Aug 28 2012

CROSSREFS

Subsequence of A125688: a(n) = A125688(n^2).

Cf. A215933, A215934.

Cf. A000040, A010051.

Sequence in context: A252651 A058485 A204907 * A011326 A154826 A155994

Adjacent sequences:  A183165 A183166 A183167 * A183169 A183170 A183171

KEYWORD

nonn

AUTHOR

Zak Seidov, Aug 27 2012

STATUS

approved

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Last modified November 20 12:30 EST 2017. Contains 294971 sequences.