This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A079790 #10 Dec 04 2024 20:38:18
%S A079790 1,1,1,1,1,1,1,1,1,3,2,3,3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,3,3,2,3,
%T A079790 3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,3,3,2,3,3,
%U A079790 3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,3,3,2,4,5,6,6,6,6
%N A079790 a(n) = number of m <= n which can be obtained by deleting digits from n.
%C A079790 a(n) = A120004(n) for n <= 100. a(101) = #{0, 1, 10, 11, 101} = 5; a(102) = #{0, 1, 2, 10, 12, 102} = 6. - _Reinhard Zumkeller_, Jun 15 2006
%H A079790 Robert Israel, <a href="/A079790/b079790.txt">Table of n, a(n) for n = 1..10000</a>
%e A079790 a(124)=7 and the numbers are 1,2,4,12,14,24,124.
%p A079790 f:= proc(n) local L,V;
%p A079790 L:= convert(n,base,10);
%p A079790 V:= convert(map(t -> L[t], combinat:-powerset([$1..nops(L)])),set) minus {[]};
%p A079790 V:= map(proc(t) local i; add(t[i]*10^(i-1),i=1..nops(t)) end proc,V);
%p A079790 nops(select(t -> t <= n, V))
%p A079790 end proc:
%p A079790 map(f, [$1..100]); # _Robert Israel_, Dec 03 2024
%K A079790 base,easy,nonn
%O A079790 1,10
%A A079790 _Amarnath Murthy_, Feb 04 2003
%E A079790 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003
%E A079790 Corrected and extended by _Reinhard Zumkeller_, Jun 15 2006