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A085257 Number of ways to write n as sum of a powerful and a squarefree number. 2
0, 1, 1, 1, 1, 2, 2, 1, 2, 3, 4, 2, 1, 4, 4, 2, 2, 4, 4, 2, 3, 4, 5, 2, 2, 4, 5, 3, 3, 7, 5, 4, 4, 5, 6, 2, 6, 9, 8, 4, 4, 9, 6, 4, 4, 8, 8, 4, 5, 7, 8, 3, 4, 6, 8, 5, 4, 6, 7, 5, 4, 9, 7, 4, 6, 10, 8, 5, 7, 9, 9, 3, 7, 10, 10, 2, 6, 12, 8, 5, 4, 10, 11, 5, 6, 11, 12, 5, 6, 8, 9, 6, 8, 11, 11, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

a(n)>0 for n>1 (proof?);

a(A085258(n))=n and a(i)<>n for i < A085258(n).

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Powerful Number

Eric Weisstein's World of Mathematics, Squarefree

EXAMPLE

a(10)=3: 10 = 1+9=A005117(1)+A001694(4) =

2+8=A005117(2)+A001694(3) = 6+4=A005117(5)+A001694(2).

CROSSREFS

Sequence in context: A071444 A232441 A328701 * A230507 A259910 A072549

Adjacent sequences:  A085254 A085255 A085256 * A085258 A085259 A085260

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jun 23 2003

STATUS

approved

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Last modified January 19 00:40 EST 2020. Contains 331030 sequences. (Running on oeis4.)