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A080463 Sum of the two numbers formed by alternate digits of n. 6
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, 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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

First 99 terms match with those of A007953.

They also match A209685. - M. F. Hasler, Jan 10 2016

LINKS

M. F. Hasler, Table of n, a(n) for n = 0..10000

FORMULA

From Robert Israel, Jan 10 2016: (Start)

f(n) = n mod 10 + floor(n/10) mod 10 + 10*f(floor(n/100)).

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).

(End)

EXAMPLE

a(132546) = 124 + 356 = 480.

MAPLE

f:= proc(n) option remember; n mod 10 + (floor(n/10) mod 10) + 10*procname(floor(n/100)) end proc:

f(0):= 0:

seq(f(n), n=0..1000); # Robert Israel, Jan 10 2016

PROG

(PARI) A080463(n)=abs(vector(#n=digits(n), j, 10^((#n-j)\2))*n~) \\ M. F. Hasler, Jan 10 2016

CROSSREFS

Cf. A007953, A080464, A080465.

Sequence in context: A033930 A076314 A007953 * A209685 A114570 A247796

Adjacent sequences:  A080460 A080461 A080462 * A080464 A080465 A080466

KEYWORD

base,easy,nonn,look

AUTHOR

Amarnath Murthy, Mar 02 2003

EXTENSIONS

More terms from Ray Chandler, Oct 11 2003

Extended to offset 0 and b-file by M. F. Hasler, Jan 10 2016

STATUS

approved

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Last modified August 18 13:25 EDT 2019. Contains 326100 sequences. (Running on oeis4.)