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A089185 Numbers n with following property: suppose n^2 = d1 d2 d3 ...dk in decimal; then d1! + d2! + ... + dk! is a square. 2
1, 11, 12, 21, 43, 190, 216, 251, 258, 370, 384, 408, 440, 462, 669, 762, 804, 809, 871, 884, 919, 1188, 1519, 1520, 1521, 1790, 1800, 1875, 2305, 2312, 2538, 2997, 3151, 3210, 3362, 3474, 4026, 4561, 5110, 5490, 5521, 5569, 5726, 5762, 5785, 7216, 7521 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

a(4)=21: 21^2=441, (4!+4!+1!)^(1/2)=7.

MAPLE

filter:= n -> issqr(add(d!, d=convert(n^2, base, 10))):

select(filter, [$1..10^4]); # Robert Israel, Mar 18 2018

CROSSREFS

Sequence in context: A153146 A132359 A131363 * A098754 A098752 A240763

Adjacent sequences:  A089182 A089183 A089184 * A089186 A089187 A089188

KEYWORD

nonn,base

AUTHOR

Yalcin Aktar, Dec 07 2003

EXTENSIONS

More terms from Yalcin Aktar, Mar 02 2007

STATUS

approved

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Last modified June 17 19:57 EDT 2021. Contains 345085 sequences. (Running on oeis4.)