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Search: id:A075308
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| A075308 |
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Number of n-digit perfect powers. |
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+0
11
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| 4, 8, 28, 84, 242, 744, 2284, 7096, 22179, 69561, 218759, 689206, 2173942, 6862783, 21676671, 68493153, 216477260, 684309327, 2163434093, 6840212693, 21628140126, 68388775913, 216252650605, 683825838922
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OFFSET
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1,1
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COMMENT
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Starting with n=2, a(n)=A070428(n) - A070428 (n-1). E.g. a(3)=28 = A070428(3) - A070428 (2). = 41-13 ( in A070428 offset is 0).
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EXAMPLE
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a(2)=8 because there are 8 2-digit pp's: 16, 25, 27, 32, 36, 49, 64, 81.
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CROSSREFS
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Cf. A001597, A070428.
Sequence in context: A105723 A143555 A025234 this_sequence A020331 A082595 A080072
Adjacent sequences: A075305 A075306 A075307 this_sequence A075309 A075310 A075311
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KEYWORD
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easy,nonn,base
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Oct 11 2002
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