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Search: id:A125433
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| A125433 |
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Number of base 21 circular n-digit numbers with adjacent digits differing by 7 or less. |
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+0
1
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| 1, 21, 259, 2709, 32627, 401401, 5043115, 64108009, 821245795, 10571373945, 136492942139, 1765686281633, 22868116742483, 296391829451401, 3843261172758763, 49848967431027409, 646678407486881219
(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(7) for base>=7.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]`-$[(i+1)mod N]`>7)+($[(i+1)mod N]`-$[i]`>7))
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CROSSREFS
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Sequence in context: A023019 A036220 A022649 this_sequence A135122 A045505 A092794
Adjacent sequences: A125430 A125431 A125432 this_sequence A125434 A125435 A125436
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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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