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A032940 Numbers whose base-5 representation Sum_{i=0..m} d(i)*5^(m-i) has d(i)=0 for all odd i. 1

%I #15 Feb 12 2021 22:03:12

%S 1,2,3,4,5,10,15,20,25,26,27,28,29,50,51,52,53,54,75,76,77,78,79,100,

%T 101,102,103,104,125,130,135,140,145,250,255,260,265,270,375,380,385,

%U 390,395,500,505,510,515,520,625,626,627,628,629

%N Numbers whose base-5 representation Sum_{i=0..m} d(i)*5^(m-i) has d(i)=0 for all odd i.

%H Robert Israel, <a href="/A032940/b032940.txt">Table of n, a(n) for n = 1..10000</a>

%p f:= proc(n,j) local L,m;

%p L:= convert(n,base,5);

%p m:= nops(L);

%p j*add(L[i+1]*5^(2*i),i=0..m-1)

%p end proc:

%p seq(seq(seq(f(n,j),n=5^k..5^(k+1)-1),j=[1,5]),k=0..2); # _Robert Israel_, Nov 15 2020

%Y Cf. A007091 (numbers in base 5).

%K nonn,base

%O 1,2

%A _Clark Kimberling_

%E Definition corrected by _Robert Israel_, Nov 15 2020

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Last modified September 11 17:23 EDT 2024. Contains 375839 sequences. (Running on oeis4.)