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Numbers the product of whose nonzero digits is a perfect square.

3

`%I #13 Sep 17 2024 12:34:13
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`%S 1,4,9,10,11,14,19,22,28,33,40,41,44,49,55,66,77,82,88,90,91,94,99,
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`%T 100,101,104,109,110,111,114,119,122,128,133,140,141,144,149,155,166,
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`%U 177,182,188,190,191,194,199,202,208,212,218,220,221,224,229,236,242,248
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`%N Numbers the product of whose nonzero digits is a perfect square.
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`%H Harry J. Smith, <a href="/A062371/b062371.txt">Table of n, a(n) for n = 1..1000</a>
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`%e 128 is a member as 1*2*8 = 16 is a square. 140 is also a member as 1*4 = 4.
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`%o (PARI) ok(k)={my(d=digits(k)); issquare(prod(i=1, #d, if(d[i], d[i], 1)))} \\ _Andrew Howroyd_, Sep 17 2024
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`%Y Cf. A062372.
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`%K nonn,base,easy
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`%O 1,2
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`%A _Amarnath Murthy_, Jun 26 2001
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`%E Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jul 06 2001
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`%E Offset changed by _Andrew Howroyd_, Sep 17 2024
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