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A065741 Largest square <= sum of squares of divisors of n. 12
1, 4, 9, 16, 25, 49, 49, 81, 81, 121, 121, 196, 169, 225, 256, 324, 289, 441, 361, 529, 484, 576, 529, 841, 625, 841, 784, 1024, 841, 1296, 961, 1296, 1156, 1444, 1296, 1849, 1369, 1764, 1681, 2209, 1681, 2500, 1849, 2500, 2304, 2601, 2209, 3364, 2401 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

FORMULA

a(n)=A048760[A001157(n)]

MATHEMATICA

Table[Floor[Sqrt[DivisorSigma[2, w]]//N]^2, {w, 1, 100}]

PROG

(PARI) sigma2(n)= { local(d, s=0); d=divisors(n); for(i=1, length(d), s+=d[i]^2); return(s) } { for (n=1, 1000, a=sqrtint(sigma2(n))^2; write("b065741.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 29 2009]

CROSSREFS

Cf. A048760, A001157, A065730-A065741

Sequence in context: A008024 A008056 A108612 * A188061 A069560 A075494

Adjacent sequences:  A065738 A065739 A065740 * A065742 A065743 A065744

KEYWORD

easy,nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Nov 15 2001

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Last modified February 15 23:53 EST 2012. Contains 205860 sequences.