login
A333492
Position of first appearance of n in A271410 (LCM of binary indices).
4
1, 2, 4, 8, 16, 6, 64, 128, 256, 18, 1024, 12, 4096, 66, 20, 32768, 65536, 258, 262144, 24, 68, 1026, 4194304, 132, 16777216, 4098, 67108864, 72, 268435456, 22, 1073741824, 2147483648, 1028, 65538, 80, 264, 68719476736, 262146, 4100, 144, 1099511627776, 70, 4398046511104
OFFSET
1,2
COMMENTS
A binary index of n is any position of a 1 in its reversed binary expansion. The binary indices of n are row n of A048793.
LINKS
EXAMPLE
The sequence together with the corresponding binary expansions and binary indices begins:
1: 1 ~ {1}
2: 10 ~ {2}
4: 100 ~ {3}
8: 1000 ~ {4}
16: 10000 ~ {5}
6: 110 ~ {2,3}
64: 1000000 ~ {7}
128: 10000000 ~ {8}
256: 100000000 ~ {9}
18: 10010 ~ {2,5}
1024: 10000000000 ~ {11}
12: 1100 ~ {3,4}
4096: 1000000000000 ~ {13}
66: 1000010 ~ {2,7}
20: 10100 ~ {3,5}
32768: 1000000000000000 ~ {16}
65536: 10000000000000000 ~ {17}
258: 100000010 ~ {2,9}
MATHEMATICA
bpe[n_]:=Join@@Position[Reverse[IntegerDigits[n, 2]], 1];
q=Table[LCM@@bpe[n], {n, 10000}];
Table[Position[q, i][[1, 1]], {i, First[Split[Union[q], #1+1==#2&]]}]
CROSSREFS
The version for prime indices is A330225.
The version for standard compositions is A333225.
Let q(k) be the binary indices of k:
- The sum of q(k) is A029931(k).
- The elements of q(k) are row k of A048793.
- The product of q(k) is A096111(k).
- The LCM of q(k) is A271410(k).
- The GCD of q(k) is A326674(k).
GCD of prime indices is A289508.
LCM of prime indices is A290103.
LCM of standard compositions is A333226.
Sequence in context: A167425 A212638 A016018 * A228845 A228846 A070336
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 28 2020
EXTENSIONS
Terms a(23) and beyond from Giovanni Resta, Mar 29 2020
STATUS
approved