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Search: id:A125477
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| A125477 |
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Number of base 20 circular n-digit numbers with adjacent digits differing by 9 or less. |
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+0
1
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| 1, 20, 290, 3710, 53630, 790670, 11804384, 177140396, 2664526934, 40121436206, 604415162550, 9107184376046, 137237515952000, 2068136987970632, 31166901568081520, 469690150305370760, 7078330364431520854
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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[Empirical] a(base,n)=a(base-1,n)+F(9) for base>=9.int(n/2)+1 and F(d) is the largest coefficient in (1+x+...+x^(2d))^n
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PROGRAM
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(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>9)+($[(i+1)mod N]`-$[i]`>9))
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CROSSREFS
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Sequence in context: A016314 A021164 A017918 this_sequence A016261 A016309 A016259
Adjacent sequences: A125474 A125475 A125476 this_sequence A125478 A125479 A125480
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhhardin(AT)att.net), Dec 28 2006
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