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Search: id:A094406
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| A094406 |
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Smallest unhappy number that takes n steps to reach any of the unhappy cycle (4, 16, 37, 58, 89, 145, 42, 20) under iteration of sum of squares of digits map. |
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+0
1
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| 4, 2, 11, 15, 5, 3, 14, 45, 36, 6, 112, 269, 15999
(list; graph; listen)
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OFFSET
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4,1
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COMMENT
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This sequence is an analogue of sequence A001273 with the unhappy numbers instead of the happy numbers.
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LINKS
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W. Schneider, Unhappy Numbers.
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EXAMPLE
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15 is the fourth term because: 15: 1^2 + 5^2 = 26 / 26: 2^2 + 6^2 = 40 / 40: 4^2 + 0^2 = 16 and 16 is a member of the unhappy number series (4, 16, 37, 58, 89, 145, 42, 20)
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CROSSREFS
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Cf. A001273.
Sequence in context: A128781 A135440 A091484 this_sequence A092952 A010318 A137447
Adjacent sequences: A094403 A094404 A094405 this_sequence A094407 A094408 A094409
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KEYWORD
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nonn
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AUTHOR
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Sergio Pimentel (ferdiego(AT)cox-internet.com), Apr 30 2004
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EXTENSIONS
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The next term, 577999999999....999999999999 (199 digits) is too large to include.
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