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A340773
Numbers that can be written as a*2^b+b*2^c+c*2^a where a,b,c are positive integers.
1
6, 10, 16, 24, 26, 36, 38, 44, 52, 54, 56, 64, 72, 76, 78, 80, 88, 92, 104, 112, 114, 116, 118, 120, 132, 144, 154, 160, 168, 180, 188, 190, 192, 202, 208, 212, 216, 232, 240, 244, 248, 264, 266, 272, 274, 284, 292, 296, 312, 320, 324, 326, 340, 352, 362, 364, 368, 384, 392, 406, 408, 416, 424
OFFSET
1,1
LINKS
Mathematics StackExchange, Ordered triple condition
EXAMPLE
a(3) = 16 is a term because 16 = 2*2^1+1*2^2+2*2^2 (also 3*2^1+1*2^1+1*2^3).
MAPLE
N:= 1000: # for terms <= N
R:= NULL:
for a from 1 while 2^a < N do
for b from 1 to a while a*2^b + 2*b + 2^a <= N do
for c from 1 to a do
v:= a*2^b + b*2^c + c*2^a;
if v > N then break fi;
R:= R, v
od od od:
sort(convert({R}, list));
CROSSREFS
Sequence in context: A301724 A315349 A315350 * A114975 A230276 A079329
KEYWORD
nonn
AUTHOR
Robert Israel, Jan 20 2021
STATUS
approved