OFFSET
1,1
COMMENTS
a(A000389(k)) = (161*3^(k-5)-1)/2 for k >= 5. - Robert Israel, Sep 21 2020
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
f:= proc(d) local C, c;
C:= combinat:-choose(d, 4);
c:=(3^(d)-1)/2;
op(sort([seq(c+add(3^(i-1), i=t), t=C)]))
end proc:
seq(f(d), d=4..8); # Robert Israel, Sep 21 2020
MATHEMATICA
A044993list[upto_]:=Select[Range[upto], DigitCount[#, 3, 0]==0&&DigitCount[#, 3, 2]==4&]; A044993list[3000] (* Paolo Xausa, Aug 03 2023 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved