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A053186 Square excess of n: difference between n and largest square <= n. 28
0, 0, 1, 2, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Comment from David W. Wilson, Jan 05 2009: (Start)

More generally we may consider sequences defined by:

a(n) = n^j - (largest k^th power <= n^j),

a(n) = n^j - (largest k^th power < n^j),

a(n) = (largest k^th power >= n^j) - n^j,

a(n) = (largest k^th power > n^j) - n^j,

for small values of j and k.

The present entry is the first of these with j = 1 and n = 2.

It might be interesting to add further examples to the OEIS. (End)

a(A000290(n)) = 0; a(A005563(n)) = 2*n. [Reinhard Zumkeller, May 20 2009]

0 ^ a(n) = A010052(n). [Reinhard Zumkeller, Feb 12 2012]

REFERENCES

S. H. Weintraub, An interesting recursion, Amer. Math. Monthly, 111 (No. 6, 2004), 528-530.

LINKS

_Reinhard Zumkeller_, Table of n, a(n) for n = 0..10000

H. Bottomley, Illustration of A000196, A048760, A053186

M. Somos, Sequences used for indexing triangular or square arrays

FORMULA

a(n) = n-A048760(n) =n-floor(sqrt(n))^2

a(n)=f(n,1) with f(n,m) = if n<m then n else f(n-m,m+2). [From Reinhard Zumkeller, May 20 2009]

MAPLE

S:=proc(n) if issqr(n) then RETURN(0); fi; n-(floor(sqrt(n)))^2; end;

MATHEMATICA

f[n_] := n - (Floor@ Sqrt@ n)^2; Table[f@ n, {n, 0, 94}] [From Robert G. Wilson v, Jan 23 2009]

PROG

(PARI) a(n)=if(n<0, 0, n-sqrtint(n)^2)

(Haskell)

a053186 n = n - a048760 n

a053186_list = f 0 0 (map fst $ iterate (\(y, z) -> (y+z, z+2)) (0, 1))

   where f e x ys'@(y:ys) | x < y  = e : f (e + 1) (x + 1) ys'

                          | x == y = 0 : f 1 (x + 1) ys

-- Reinhard Zumkeller, Apr 27 2012

CROSSREFS

Cf. A002262, A048760. A071797(n)=1+a(n-1).

A002262. [From Reinhard Zumkeller, May 20 2009]

Cf. A048760, A000196.

Sequence in context: A201076 A201079 A049260 * A066628 A218601 A135317

Adjacent sequences:  A053183 A053184 A053185 * A053187 A053188 A053189

KEYWORD

easy,nonn

AUTHOR

Henry Bottomley, Mar 01 2000

STATUS

approved

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Last modified May 22 01:50 EDT 2013. Contains 225509 sequences.