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A333225
Position of first appearance of n in A333226 (LCMs of compositions in standard order).
3
1, 2, 4, 8, 16, 18, 64, 128, 256, 66, 1024, 68, 4096, 258, 132, 32768, 65536, 1026, 262144, 264, 516, 4098
OFFSET
1,2
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 together with the corresponding compositions begins:
1: (1)
2: (2)
4: (3)
8: (4)
16: (5)
18: (3,2)
64: (7)
128: (8)
256: (9)
66: (5,2)
1024: (11)
68: (4,3)
4096: (13)
258: (7,2)
132: (5,3)
32768: (16)
65536: (17)
1026: (9,2)
262144: (19)
264: (5,4)
MATHEMATICA
stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n, 2]], 1], 0]]//Reverse;
q=Table[LCM@@stc[n], {n, 10000}];
Table[Position[q, i][[1, 1]], {i, First[Split[Union[q], #1+1==#2&]]}]
CROSSREFS
The version for binary indices is A333492.
The version for prime indices is A330225.
Let q(k) be the k-th composition in standard order:
- The terms of q(k) are row k of A066099.
- The sum of q(k) is A070939(k).
- The product of q(k) is A124758(k).
- The GCD of q(k) is A326674(k).
- The LCM of q(k) is A333226(k).
Sequence in context: A133809 A128700 A331579 * A212204 A184986 A018547
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Mar 26 2020
STATUS
approved