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A092383 Sum of digits of n if n odd, else sum of digits of 2n. 2
0, 1, 4, 3, 8, 5, 3, 7, 7, 9, 2, 2, 6, 4, 10, 6, 5, 8, 9, 10, 4, 3, 8, 5, 12, 7, 7, 9, 11, 11, 6, 4, 10, 6, 14, 8, 9, 10, 13, 12, 8, 5, 12, 7, 16, 9, 11, 11, 15, 13, 1, 6, 5, 8, 9, 10, 4, 12, 8, 14, 3, 7, 7, 9, 11, 11, 6, 13, 10, 15, 5, 8, 9, 10, 13, 12, 8, 14, 12, 16, 7, 9, 11, 11, 15, 13, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Inspired by Luhn algorithm for validating credit cards.

LINKS

Table of n, a(n) for n=0..86.

FORMULA

a(n) = sum of digits(if n odd then n else 2n).

EXAMPLE

a(11) = 2 = 1 + 1 (1 and 1 are the digits in 11).

a(12) = 6 = 2 + 4 (2 and 4 are the digits in 24 = 2 * 12).

MATHEMATICA

f[n_] := Plus @@ IntegerDigits[ If[ OddQ[n], n, 2n]]; Table[ f[n], {n, 0, 90}] (* Robert G. Wilson v, Mar 24 2004 *)

CROSSREFS

Cf. A092384, A093150.

Sequence in context: A021962 A097672 A103339 * A227242 A156028 A021232

Adjacent sequences:  A092380 A092381 A092382 * A092384 A092385 A092386

KEYWORD

easy,nonn,base

AUTHOR

Semaphore Corporation (help(AT)semaphorecorp.com), Mar 20 2004

EXTENSIONS

Corrected and extended by Ray Chandler, Mar 21 2004

STATUS

approved

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Last modified April 3 19:43 EDT 2020. Contains 333198 sequences. (Running on oeis4.)