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Search: id:A126396
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| A126396 |
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Number of base 9 n-digit numbers with adjacent digits differing by two or less. |
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+0
4
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| 1, 9, 39, 175, 793, 3611, 16475, 75229, 343633, 1569883, 7172423, 32769925, 149723361, 684077955, 3125520983, 14280373781, 65246447425, 298108406323, 1362045450407, 6223131628517, 28433241805745, 129910355608771
(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)+5^(n-1) for base>=2n-1; a(base,n)=a(base-1,n)+5^(n-1)-2 when base=2n-2
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PROGRAM
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(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>2)+($[i+1]`-$[i]`>2))
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CROSSREFS
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Cf. Base 9 differing by one or less A126363.
Sequence in context: A060929 A124851 A124041 this_sequence A075210 A002085 A076603
Adjacent sequences: A126393 A126394 A126395 this_sequence A126397 A126398 A126399
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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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