OFFSET
0,2
COMMENTS
The sorted sequence is A325093.
For example, 11 = 1 + 2 + 8, so a(11) = prime(1) * prime(2) * prime(8) = 114.
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
3: {2}
6: {1,2}
7: {4}
14: {1,4}
21: {2,4}
42: {1,2,4}
19: {8}
38: {1,8}
57: {2,8}
114: {1,2,8}
133: {4,8}
266: {1,4,8}
399: {2,4,8}
798: {1,2,4,8}
53: {16}
106: {1,16}
159: {2,16}
318: {1,2,16}
371: {4,16}
MAPLE
P:= [seq(ithprime(2^i), i=0..10)]:
f:= proc(n) local L, i;
L:= convert(n, base, 2);
mul(P[i]^L[i], i=1..nops(L))
end proc:
map(f, [$0..100]); # Robert Israel, Mar 28 2019
MATHEMATICA
Table[Times@@MapIndexed[If[#1==0, 1, Prime[2^(#2[[1]]-1)]]&, Reverse[IntegerDigits[n, 2]]], {n, 0, 100}]
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Gus Wiseman, Mar 27 2019
STATUS
approved