|
%I #13 Jun 29 2019 01:38:26
%S 0,1,12,24,125,139,169,185,1096,1191,1223,1243,1369,1391,1425,1461,
%T 10442,10468,10585,10613,10741,10781,10819,10851,11789,11878,11918,
%U 12732,12862,12900,12958,12998,101989,102037,102081,102133,102384,102430,102476,102528,103468,103518,103576
%N a(n) is the sum of the base-b representations of n for 2 <= b <= n+1 read in base ten.
%C Since the evaluation of n begins with base 2, the members of this sequence occupy neighborhoods in groups the size of powers of two.
%H Robert Israel, <a href="/A289335/b289335.txt">Table of n, a(n) for n = 0..7000</a>
%e a(5) = 139 because 5 in bases 2 through 6 is 101, 12, 11, 10 and 5, respectively, and (read as base-10 numbers) their sum is 139.
%p f:= proc(n) local b,t,L;
%p t:= 0;
%p for b from 2 to n+1 do
%p L:= convert(n,base,b);
%p t:= t + add(L[i]*10^(i-1),i=1..nops(L));
%p od:
%p t
%p end proc:
%p map(f, [$0..100]); # _Robert Israel_, Jul 07 2017
%t f[n_] := Sum[ FromDigits[ IntegerDigits[n, i]], {i, 2, n + 1}]; Array[f, 40, 0]
%o (PARI) a(n) = sum(k=2, n+1, fromdigits(digits(n, k), 10)); \\ _Michel Marcus_, Jul 02 2017
%K nonn,base,easy
%O 0,3
%A _Robert G. Wilson v_, Jul 02 2017
|
