The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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