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A067344 Sum of decimal digits of square of divisors of n equals sum of square of digits of n. 1
1, 21, 41, 120, 242, 312, 323, 401, 501, 1040, 1114, 1141, 1204, 1214, 1233, 1241, 1304, 1503, 2033, 2115, 2133, 2140, 2403, 3010, 3014, 3124, 3211, 3304, 3322, 4001, 4012, 4121, 4301, 4310, 5130, 10044, 10214, 10242, 10320, 10324, 11042, 11115 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

A007953[A001157(n)]=A007953[n]^2

EXAMPLE

n=51223, SquareSumDigit=25+1+4+4+9=43, Sigma[2,51223]=2623908580 with digit sum=43.

MATHEMATICA

Do[s=Apply[Plus, IntegerDigits[DivisorSigma[2, n]]]- Apply[Plus, IntegerDigits[n]^2]; If[Equal[s, 0], Print[n]], {n, 1, 10000}]

Select[Range[12000], Total[Flatten[IntegerDigits[#]^2]]== Total[ IntegerDigits[ DivisorSigma[2, #]]]&] (* Harvey P. Dale, Sep 12 2012 *)

CROSSREFS

Cf. A067342, A067343, A007953, A001157.

Sequence in context: A173960 A147273 A195034 * A053428 A123842 A247387

Adjacent sequences:  A067341 A067342 A067343 * A067345 A067346 A067347

KEYWORD

base,nonn

AUTHOR

Labos Elemer, Jan 16 2002

STATUS

approved

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Last modified October 20 03:05 EDT 2019. Contains 328244 sequences. (Running on oeis4.)