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Search: id:A125408
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| A125408 |
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Number of base 20 circular n-digit numbers with adjacent digits differing by 6 or less. |
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+0
1
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| 1, 20, 218, 1994, 21078, 227450, 2509508, 28044008, 316237326, 3587876114, 40876370578, 467018577782, 5345948876388, 61273602792708, 702905295827666, 8068104827974874, 92643421204990558, 1064070251138125106
(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(6) for base>=6.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]`-$[(i+1)mod N]`>6)+($[(i+1)mod N]`-$[i]`>6))
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CROSSREFS
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Adjacent sequences: A125405 A125406 A125407 this_sequence A125409 A125410 A125411
Sequence in context: A007744 A121204 A128823 this_sequence A140236 A004411 A140354
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhh(AT)cadence.com), Dec 28 2006
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