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A179937
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a(n) is the product of the non-palindromic divisors of n.
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2
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1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 12, 13, 14, 15, 16, 17, 18, 19, 200, 21, 1, 23, 288, 25, 338, 27, 392, 29, 4500, 31, 512, 1, 578, 35, 7776, 37, 722, 507, 8000, 41, 12348, 43, 1, 675, 1058, 47, 221184, 49, 12500, 867, 17576, 53, 26244, 1, 21952, 1083, 1682, 59
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OFFSET
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1,10
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LINKS
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FORMULA
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EXAMPLE
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For n = 20, set of non-palindromic divisors is {10, 20}; a(12) = 10*20 = 200.
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MATHEMATICA
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Table[Times@@Select[Divisors[n], !PalindromeQ[#]&], {n, 60}] (* Harvey P. Dale, May 15 2023 *)
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PROG
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(Python)
def ispal(n):
return n==int(str(n)[::-1])
s=1
for i in range(1, n+1):
if n%i==0 and not ispal(i):
s*=i
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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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EXTENSIONS
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STATUS
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approved
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