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A365258
The four digits of a(n), their three successive absolute first differences and their two successive absolute second differences are all distinct.
1
2983, 3892, 4197, 4917, 5298, 5928, 7194, 7398, 7914, 7938, 8139, 8295, 8329, 8397, 8925, 8937, 9238, 9318
OFFSET
1,1
COMMENTS
The digit 0 is never present in a(n) and never appears as a first or a second difference (as this would duplicate in both cases one of the 8 remaining digits involved).
The sequence ends with a(18) = 9318.
EXAMPLE
2983 is a term since its three successive absolute first differences 7 (= 2 - 9), 1 (= 9 - 8), 5 (= 8 - 3) and the successive absolute second differences 6 (= 7 - 1) and 4 (= 1 - 5), are nine distinct digits.
2 9 8 3
7 1 5
6 4
MATHEMATICA
Select[Range[1000, 9999], Sort@Join[IntegerDigits@#, s=Abs@Differences@IntegerDigits@#, Abs@Differences@s]==Range@9&]
CROSSREFS
KEYWORD
base,nonn,fini,full
AUTHOR
STATUS
approved