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A044818 Positive integers having distinct base-7 run lengths. 17
1, 2, 3, 4, 5, 6, 8, 16, 24, 32, 40, 48, 49, 56, 57, 58, 59, 60, 61, 62, 65, 73, 81, 89, 97, 98, 106, 112, 113, 114, 115, 116, 117, 118, 122, 130, 138, 146, 147, 155, 163, 168, 169, 170, 171, 172, 173, 174, 179, 187, 195, 196, 204, 212, 220, 224, 225, 226, 227, 228 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
40=55_7 has a single run length of 2 and is in the sequence. 211=421_7 has three runs of length 1 as is not in the sequence. - R. J. Mathar, Jan 18 2018
MAPLE
rlset := proc(L::list)
local lset, rl, i ;
lset := [] ;
rl := 1 ;
for i from 2 to nops(L) do
if op(i, L) = op(i-1, L) then
rl := rl+1 ;
else
lset := [op(lset), rl] ;
rl := 1;
end if;
end do:
lset := [op(lset), rl] ;
end proc:
isA044818 := proc(n)
local dgs, rl;
dgs := convert(n, base, 7) ;
rl := rlset(dgs) ;
if nops(rl) = nops( convert(rl, set)) then
true;
else
false;
end if;
end proc:
for n from 1 to 400 do
if isA044818(n) then
printf("%d, ", n) ;
end if;
end do: # R. J. Mathar, Jan 18 2018
CROSSREFS
Sequence in context: A039089 A044956 A297139 * A048304 A043710 A296703
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)