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A247367 Number of ways to write n as a sum of a square and a nonsquare. 3
0, 0, 1, 2, 1, 1, 3, 3, 2, 2, 2, 4, 4, 2, 4, 4, 3, 3, 4, 5, 3, 5, 5, 5, 5, 2, 4, 6, 6, 4, 6, 6, 5, 6, 4, 6, 5, 5, 7, 7, 5, 5, 7, 7, 7, 5, 7, 7, 7, 6, 5, 8, 6, 6, 8, 8, 8, 8, 6, 8, 8, 6, 8, 8, 7, 5, 9, 9, 7, 9, 9, 9, 8, 7, 7, 9, 9, 9, 9, 9, 7, 8, 8, 10, 10, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

EXAMPLE

a(10) = #{0+10, 4+6} = 2;

a(11) = #{0+11, 1+10, 4+7, 9+2} = 4;

a(12) = #{0+12, 1+11, 4+8, 9+3} = 4;

a(13) = #{0+13, 1+12} = 2;

a(14) = #{0+14, 1+13, 4+10, 9+5} = 4;

a(15) = #{0+15, 1+14, 4+11, 9+6} = 4;

a(16) = #{1+15, 4+12, 9+7} = 3;

a(17) = #{0+17, 4+13, 9+8} = 3;

a(18) = #{0+18, 1+17, 4+14, 16+2} = 4;

a(19) = #{0+19, 1+18, 4+15, 9+10, 16+3} = 5;

a(20) = #{0+20, 1+19, 9+11} = 3.

PROG

(Haskell)

a247367 n = sum $ map ((1 -) . a010052 . (n -)) $

                  takeWhile (<= n) a000290_list

CROSSREFS

Cf. A000037, A000290, A010052, A000925, A000161.

Sequence in context: A052253 A271453 A247749 * A127838 A017817 A284834

Adjacent sequences:  A247364 A247365 A247366 * A247368 A247369 A247370

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Sep 14 2014

STATUS

approved

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Last modified February 25 06:31 EST 2018. Contains 299643 sequences. (Running on oeis4.)