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A331579
Position of first appearance of n in A124758 (products of compositions in standard order).
5
1, 2, 4, 8, 16, 18, 64, 34, 36, 66, 1024, 68, 4096, 258, 132, 136, 65536, 146, 262144, 264, 516, 4098
OFFSET
1,2
COMMENTS
A composition of n is a finite sequence of positive integers summing to n. 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 list of terms together with the corresponding compositions begins:
1: (1)
2: (2)
4: (3)
8: (4)
16: (5)
18: (3,2)
64: (7)
34: (4,2)
36: (3,3)
66: (5,2)
1024: (11)
68: (4,3)
4096: (13)
258: (7,2)
132: (5,3)
136: (4,4)
65536: (17)
146: (3,3,2)
262144: (19)
264: (5,4)
MATHEMATICA
stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n, 2]], 1], 0]]//Reverse;
q=Table[Times@@stc[n], {n, 1000}];
Table[Position[q, i][[1, 1]], {i, First[Split[Union[q], #1+1==#2&]]}]
CROSSREFS
The product of prime indices is A003963.
The sum of binary indices is A029931.
The sum of prime indices is A056239.
Sums of compositions in standard order are A070939.
The product of binary indices is A096111.
All terms belong to A114994.
Products of compositions in standard order are A124758.
Sequence in context: A364061 A133809 A128700 * A333225 A212204 A184986
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Mar 20 2020
STATUS
approved