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%I #35 May 22 2021 03:10:15
%S 0,0,0,0,0,0,0,0,0,0,0,1,2,3,4,5,6,7,8,9,0,2,4,6,8,10,12,14,16,18,0,3,
%T 6,9,12,15,18,21,24,27,0,4,8,12,16,20,24,28,32,36,0,5,10,15,20,25,30,
%U 35,40,45,0,6,12,18,24,30,36,42,48,54,0,7,14,21,28,35,42,49,56,63,0,8,16,24,32,40,48,56,64,72,0,9,18,27,36,45,54,63,72,81,0,11
%N Let the decimal expansion of n be abcd...; then a(n) = (a*bcd... + b*acd... + c*abd... + d*abc... + ...) + (ab*cd... + bc*ad... + cd*ab... + ...) + ... . That is, a(n) = sum over all the digit strings of the product (number obtained by deleting a digit string) * (deleted digit string).
%C Each substring is used in only product.
%C a(n) = 0 for 0 <= n <= 10.
%H Alois P. Heinz, <a href="/A088117/b088117.txt">Table of n, a(n) for n = 0..20000</a>
%e a(1234) = (1*234 + 2*134 + 3*124 + 4*123) + (12*34 + 23*14) = 2096.
%e a(12345) = (1*2345 + 2*1345 + 3*1245 + 4*1235 + 5*1234) + (12*345 + 15*234 + 23*145 + 34*125 + 45*123) = 40650.
%p a:= n-> (s-> add(add(parse(s[i..j])*parse(cat(s[1..i-1],
%p s[j+1..length(s)])), i=1..j), j=1..length(s)-1))(""||n):
%p seq(a(n), n=0..120); # _Alois P. Heinz_, May 22 2021
%Y Cf. A007954, A088116.
%Y Different from A035930, A171765, A257850.
%K base,easy,nonn
%O 0,13
%A _Amarnath Murthy_, Sep 25 2003
%E Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, Jul 14 2007
%E a(0)=0 inserted and examples corrected by _Alois P. Heinz_, May 22 2021
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