OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
A0[1]:= {2, 4}:
A1[1]:= {1}:
A3[1]:= {3}:
A11[1]:= {}:
A13[1]:= {}:
A33[1]:= {}:
A113[1]:= {}:
A133[1]:= {}:
A333[1]:= {}:
A1133[1]:= {}:
A1333[1]:= {}:
A11333[1]:= {}:
count:= 0:
for n from 2 while count < 1000 do
A0[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A0[n-1]);
A1[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A1[n-1]) union map(t -> 5*t+1, A0[n-1]);
A3[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A3[n-1]) union map(t -> 5*t+3, A0[n-1]);
A13[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A13[n-1]) union map(t -> 5*t+1, A3[n-1]) union map(t -> 5*t+3, A1[n-1]);
A33[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A33[n-1]) union map(t -> 5*t+3, A3[n-1]);
A113[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A113[n-1]) union map(t -> 5*t+1, A13[n-1]) union map(t -> 5*t+3, A11[n-1]);
A133[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A133[n-1]) union map(t -> 5*t+1, A33[n-1]) union map(t -> 5*t+3, A13[n-1]);
A333[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A333[n-1]) union map(t -> 5*t+3, A33[n-1]);
A1133[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A1133[n-1]) union map(t -> 5*t+1, A133[n-1]) union map(t -> 5*t+3, A113[n-1]);
A1333[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A1333[n-1]) union map(t -> 5*t+1, A333[n-1]) union map(t -> 5*t+3, A133[n-1]);
A11333[n]:= map(t -> (5*t, 5*t+2, 5*t+4), A11333[n-1]) union map(t -> 5*t+1, A1333[n-1]) union map(t -> 5*t+3, A1133[n-1]);
count:= count + nops(A11333[n]);
od:
sort([seq(op(A11333[i]), i=1..n-1)]); # Robert Israel, Dec 10 2023
MATHEMATICA
Select[Range[6000], DigitCount[#, 5, 1]==2&&DigitCount[#, 5, 3]==3&] (* Harvey P. Dale, Feb 25 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved