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A019544 Squares whose digits are squares. 9
0, 1, 4, 9, 49, 100, 144, 400, 441, 900, 1444, 4900, 9409, 10000, 10404, 11449, 14400, 19044, 40000, 40401, 44100, 44944, 90000, 144400, 419904, 490000, 491401, 904401, 940900, 994009, 1000000, 1004004, 1014049, 1040400, 1100401, 1144900, 1440000, 1904400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Are there infinitely many terms not divisible by 100? - Charles R Greathouse IV, Sep 19 2012

Yes. For example, the squares of the type (k*10^m+1)^2, where m>0 and k = 2, 70, 970, 202470000  or  m>1 and k = 10^m-3, belong to the sequence. - Bruno Berselli, Jan 10 2013

LINKS

Robert Israel, Table of n, a(n) for n = 1..544

Sylvester Smith, A Set of Conjectures on Smarandache Sequences, Bulletin of Pure and Applied Sciences, (Bombay, India), Vol. 15 E (No. 1), 1996, pp. 101-107.

Eric Weisstein's World of Mathematics, Smarandache Sequences

FORMULA

a(n) = A285550(n)^2. - Alois P. Heinz, Apr 21 2017

MAPLE

filter:= n -> convert(convert(n, base, 10), set) subset {0, 1, 4, 9}:

select(filter, [seq(n^2, n=1..10^5)]); # Robert Israel, Aug 14 2018

PROG

(MAGMA) [n^2: n in [0..2000] | forall{d: d in Intseq(n^2) | d in [0, 1, 4, 9]}]; // Bruno Berselli, Jan 10 2013

CROSSREFS

Cf. A285550.

Sequence in context: A055812 A268099 A061867 * A053059 A006716 A068809

Adjacent sequences:  A019541 A019542 A019543 * A019545 A019546 A019547

KEYWORD

nonn,base

AUTHOR

R. Muller

EXTENSIONS

Offset changed to 1 by Alois P. Heinz, Apr 21 2017

STATUS

approved

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Last modified December 16 01:32 EST 2019. Contains 330013 sequences. (Running on oeis4.)