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A032986
Numbers with the property that all pairs of consecutive base-9 digits differ by more than 2.
0
1, 2, 3, 4, 5, 6, 7, 8, 13, 14, 15, 16, 17, 23, 24, 25, 26, 27, 33, 34, 35, 36, 37, 43, 44, 45, 46, 47, 53, 54, 55, 56, 57, 63, 64, 65, 66, 67, 72, 73, 74, 75, 76, 77, 117, 118, 124, 125, 126, 127, 128, 134, 135, 136, 137, 138, 144, 145, 146
OFFSET
1,2
COMMENTS
Comments from Huen Yeong Kong (cosmology(AT)pacific.net.sg), Sep 19 2008: (Start)
Consider the sequence with the first eight terms deleted: 13, 14, 15, 16, 17, 23, 24, 25, 26, 27, 33, 34, 35, 36, 37, 43, 44, 45, 46, 47, 53, 54, 55, ...
This sequence extends to infinity starting from the first 5-tuple cluster of 13,14,15,16,17 with higher clusters separated by multiples of 10 intervals. This sequence extended to infinity is completely devoid of twin primes.
Example: For n = 10, the sequence generated is: [[13, 14, 15, 16, 17], [23, 24, 25, 26, 27], [33, 34, 35, 36, 37], [43, 44, 45, 46, 47], [53, 54, 55, 56, 57], [63, 64, 65, 66, 67], [73, 74, 75, 76, 77], [83, 84, 85, 86, 87], [93, 94, 95, 96, 97]]
Using Macsyma Symbolic Software we can write: makelist( [6+i*10-10-3,6+i*10-10-2,6+i*10-10-1, 6+i*10-10, 6+i*10-10+1], i,2,n); (End)
MATHEMATICA
Select[Range[200], Min[Abs[Differences[IntegerDigits[#, 9]]]]>2&] (* Harvey P. Dale, Aug 02 2024 *)
CROSSREFS
Cf. A007095.
Sequence in context: A165306 A254116 A254115 * A032977 A133245 A200374
KEYWORD
nonn,base
STATUS
approved