login
A333218
Numbers k such that the k-th composition in standard order is a permutation (of an initial interval).
64
0, 1, 5, 6, 37, 38, 41, 44, 50, 52, 549, 550, 553, 556, 562, 564, 581, 582, 593, 600, 610, 616, 649, 652, 657, 664, 708, 712, 786, 788, 802, 808, 836, 840, 16933, 16934, 16937, 16940, 16946, 16948, 16965, 16966, 16977, 16984, 16994, 17000, 17033, 17036, 17041
OFFSET
1,3
COMMENTS
The k-th composition in standard order (row k of A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again.
EXAMPLE
The sequence of terms together with their corresponding compositions begins:
0: () 593: (3,2,4,1) 16937: (5,4,2,3,1)
1: (1) 600: (3,2,1,4) 16940: (5,4,2,1,3)
5: (2,1) 610: (3,1,4,2) 16946: (5,4,1,3,2)
6: (1,2) 616: (3,1,2,4) 16948: (5,4,1,2,3)
37: (3,2,1) 649: (2,4,3,1) 16965: (5,3,4,2,1)
38: (3,1,2) 652: (2,4,1,3) 16966: (5,3,4,1,2)
41: (2,3,1) 657: (2,3,4,1) 16977: (5,3,2,4,1)
44: (2,1,3) 664: (2,3,1,4) 16984: (5,3,2,1,4)
50: (1,3,2) 708: (2,1,4,3) 16994: (5,3,1,4,2)
52: (1,2,3) 712: (2,1,3,4) 17000: (5,3,1,2,4)
549: (4,3,2,1) 786: (1,4,3,2) 17033: (5,2,4,3,1)
550: (4,3,1,2) 788: (1,4,2,3) 17036: (5,2,4,1,3)
553: (4,2,3,1) 802: (1,3,4,2) 17041: (5,2,3,4,1)
556: (4,2,1,3) 808: (1,3,2,4) 17048: (5,2,3,1,4)
562: (4,1,3,2) 836: (1,2,4,3) 17092: (5,2,1,4,3)
564: (4,1,2,3) 840: (1,2,3,4) 17096: (5,2,1,3,4)
581: (3,4,2,1) 16933: (5,4,3,2,1) 17170: (5,1,4,3,2)
582: (3,4,1,2) 16934: (5,4,3,1,2) 17172: (5,1,4,2,3)
MATHEMATICA
stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n, 2]], 1], 0]]//Reverse;
Select[Range[0, 1000], #==0||UnsameQ@@stc[#]&&Max@@stc[#]==Length[stc[#]]&]
CROSSREFS
A superset of A164894.
Also a superset of A246534.
Not requiring the parts to be distinct gives A333217.
Sequence in context: A253192 A036254 A047170 * A349051 A137254 A262308
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 16 2020
STATUS
approved