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A219032
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Number of distinct squares as subwords of decimal representation of n-th square.
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3
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1, 1, 1, 1, 2, 1, 1, 3, 2, 2, 3, 2, 3, 4, 3, 2, 2, 2, 2, 3, 3, 3, 2, 2, 1, 2, 1, 2, 2, 3, 3, 3, 4, 4, 2, 4, 3, 4, 4, 2, 4, 4, 4, 5, 4, 3, 3, 3, 3, 4, 3, 3, 3, 3, 4, 3, 3, 5, 4, 4, 3, 2, 2, 2, 4, 4, 2, 3, 2, 3, 6, 4, 3, 2, 2, 3, 1, 2, 3, 3, 5, 2, 2, 2, 2, 3
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OFFSET
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0,5
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COMMENTS
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a(n) is the number of squares in n-th row of triangle A219031.
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LINKS
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FORMULA
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EXAMPLE
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. -----------------------------
. 20 [0, 4, 40, 400] a(20) = #{0, 4, 400} = 3;
. 21 [1, 4, 41, 44, 441] a(21) = #{1, 4, 441} = 3;
. 22 [4, 8, 48, 84, 484] a(22) = #{4, 484} = 2;
. 23 [2, 5, 9, 29, 52, 529] a(23) = #{9, 529} = 2;
. 24 [5, 6, 7, 57, 76, 576] a(24) = #{576} = 1;
. 25 [2, 5, 6, 25, 62, 625] a(25) = #{25, 625} = 2.
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PROG
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(Haskell)
a219032 = sum . map a010052 . a219031_row
(Python)
from sympy import integer_nthroot
s = str(n*n)
m = len(s)
return len(set(filter(lambda x: integer_nthroot(x, 2)[1], (int(s[i:j]) for i in range(m) for j in range(i+1, m+1))))) # Chai Wah Wu, Oct 19 2021
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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