[seqfan] Absolute diff and sums not to be shared
Eric Angelini
Eric.Angelini at kntv.be
Sat Feb 7 23:23:29 CET 2015
Hello SeqFans,
We want S to be a permutation of the integers >0;
We want S to be the lexicographically first seq of its kind (see below);
If we take two adjacent integers of S, say p & q, we want that:
-> no other pair of adjacent integers in S shares the abs. diff. |p-q|
-> no other pair of adjacent integers in S shares the sum (p+q)
-> no |p-q|=(p'+q') with p'and q' being two other adjacent integers in S.
So S is extended with the smallest integer n such that neither |(n-1)-n|
nor [(n-1)+n] has occurred before as a sum or as a diff. of two adjacent
integers in S.
Sum 3 6 12 11 13 28 27 32 29 22
S(n)= 1 2 4 8 3 10 18 9 23 6 16 ...
Dif 1 2 4 5 7 8 9 14 17 10
Hope this is not old hat,
Best,
É.
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