OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
Res:= NULL:
for d from 7 to 8 do
for i from 0 to d-7 do
L:= [0$4, 3$3, 1$i, 2$(d-7-i)];
P:= remove(t -> t[-1]=0, combinat:-permute(L));
Res:= Res, op(map(t -> add(t[i]*4^(i-1), i=1..d), P));
od od:
sort([Res]); # Robert Israel, Feb 27 2018
MATHEMATICA
Select[Range[20000], DigitCount[#, 4, 0]==4&&DigitCount[#, 4, 3]==3&] (* Harvey P. Dale, Sep 22 2024 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved