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%I #15 Jan 11 2016 03:22:10
%S 0,1,2,3,4,5,6,7,8,9,1,2,3,4,5,6,7,8,9,10,2,3,4,5,6,7,8,9,10,11,3,4,5,
%T 6,7,8,9,10,11,12,4,5,6,7,8,9,10,11,12,13,5,6,7,8,9,10,11,12,13,14,6,
%U 7,8,9,10,11,12,13,14,15,7,8,9,10,11,12,13,14,15,16,8,9,10,11,12,13,14,15,16
%N Sum of the two numbers formed by alternate digits of n.
%C First 99 terms match with those of A007953.
%C They also match A209685. - _M. F. Hasler_, Jan 10 2016
%H M. F. Hasler, <a href="/A080463/b080463.txt">Table of n, a(n) for n = 0..10000</a>
%F From _Robert Israel_, Jan 10 2016: (Start)
%F f(n) = n mod 10 + floor(n/10) mod 10 + 10*f(floor(n/100)).
%F G.f. G(x) satisfies G(x) = (x + 2x^2 + ... + 9x^9)/(1-x^10) + (x^10 + 2 x^20 + ... + 9 x^90)/((1-x)(1+x^10+...+x^90) + 10 (1 + x + ... + x^99) G(x^10).
%F (End)
%e a(132546) = 124 + 356 = 480.
%p f:= proc(n) option remember; n mod 10 + (floor(n/10) mod 10) + 10*procname(floor(n/100)) end proc:
%p f(0):= 0:
%p seq(f(n),n=0..1000); # _Robert Israel_, Jan 10 2016
%o (PARI) A080463(n)=abs(vector(#n=digits(n),j,10^((#n-j)\2))*n~) \\ _M. F. Hasler_, Jan 10 2016
%Y Cf. A007953, A080464, A080465.
%K base,easy,nonn,look
%O 0,3
%A _Amarnath Murthy_, Mar 02 2003
%E More terms from _Ray Chandler_, Oct 11 2003
%E Extended to offset 0 and b-file by _M. F. Hasler_, Jan 10 2016
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