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%I A156207
%S A156207 1,2,3,4,5,6,7,8,9,1,3,5,7,9,11,13,15,17,19,2,4,6,8,10,12,14,16,18,20,
               3,
%T A156207 5,7,9,11,13,15,17,19,21,4,6,8,10,12,14,16,18,20,22,5,7,9,11,13,15,17,
%U A156207 19,21,23,6,8,10,12,14,16,18,20,22,24,7,9,11,13,15,17,19,21,23,25,8,10
%N A156207 Sum of of the products of the digits in n and their position m in n.
%C A156207 1,2,3,4,5,6,7,8,9,19 are the only numbers such that a(n) = n. For the
%C A156207 case of a 2-digit number, let 10a+b = a+2b.Then 9a = b so a=1 and b = 
               9.
%F A156207 Given a number n with m digits d1d2d3...dm, a(n) = d1*1+d2*2+d3*3+...+dm*m.
%e A156207 For n=19 we have 1*1 + 2*9 = 19, the 14-th entry in the sequence.
%o A156207 (PARI) g1(n) = for(j=1,n,print1(g(j)","))
%o A156207 g(n) = v=Vec((Str(n)));sum(x=1,length(v),x*eval(v[x]))
%Y A156207 Sequence in context: A115026 A101337 A135208 this_sequence A061486 A138470 
               A112875
%Y A156207 Adjacent sequences: A156204 A156205 A156206 this_sequence A156208 A156209 
               A156210
%K A156207 base,nonn
%O A156207 1,2
%A A156207 Cino Hilliard (hillcino368(AT)hotmail.com), Feb 05 2009, Feb 07 2009

    
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Last modified December 20 13:54 EST 2009. Contains 171081 sequences.


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