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Powers of 7 written backwards.
4

%I #11 Apr 09 2015 11:14:36

%S 1,7,94,343,1042,70861,946711,345328,1084675,70635304,942574282,

%T 3476237791,10278214831,70401098869,948270322876,3499051657474,

%U 10696503923233,702789315036232,9440197953148261,34137358159889311

%N Powers of 7 written backwards.

%H Alois P. Heinz, <a href="/A071584/b071584.txt">Table of n, a(n) for n = 0..1000</a>

%p a:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||(7^n)):

%p seq(a(n), n=0..50); # _Alois P. Heinz_, Apr 09 2015

%t FromDigits[Reverse[IntegerDigits[#]]]&/@(7^Range[0,20]) (* _Harvey P. Dale_, Apr 29 2012 *)

%o (PARI) for(i=1,50,n=5^i; s=ceil(log(n)/log(10)); print1(sum(i=0,s,10^(s-i-1)*(floor(n/10^i)-10*floor(n/10^(i+1)))),","))

%K easy,nonn,base

%O 0,2

%A _Benoit Cloitre_, Jun 01 2002