OFFSET
1,3
LINKS
Zhi-Wei Sun, On permutations of {1, ..., n} and related topics, J Algebr Comb 54, 893-912 (2021); Theorem 1.2, page 895.
EXAMPLE
The triangle begins
1,
1, 2,
3, 2, 1,
3, 2, 1, 4,
1, 2, 5, 4, 3,
1, 6, 5, 4, 3, 2,
7, 6, 5, 4, 3, 2, 1,
7, 6, 5, 4, 3, 2, 1, 8,
...
Row 5: [1, 2, 5, 4, 3] + [1, 2, 3, 4, 5] = [2, 4, 8, 8, 8]; only powers of 2 in the vector of sums.
PROG
(PARI) a375301_row(n) = forperm(n, p, my(f=1); for(k=1, n, my(s=p[k]+k); if(2^valuation(s, 2)!=s, f=0; break)); if(f==1, return(Vec(p))))
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Hugo Pfoertner, Aug 25 2024
STATUS
approved