The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A008460 Take sum of squares of digits of previous term; start with 6. 14
6, 36, 45, 41, 17, 50, 25, 29, 85, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4, 16, 37, 58, 89, 145, 42, 20, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
REFERENCES
R. Honsberger, Ingenuity in Mathematics, Random House, 1970, p. 83.
LINKS
Arthur Porges, A set of eight numbers, Amer. Math. Monthly 52 (1945), 379-382.
FORMULA
Periodic with period 8.
a(13+n) = A080709(n). - M. F. Hasler, May 24 2009
MATHEMATICA
NestList[Total[IntegerDigits[#]^2]&, 6, 80] (* Vincenzo Librandi, Jan 29 2013 *)
PROG
(PARI) A008460(n)=[6, 36, 45, 41, 17, 50, 25, 29, 85, 89, 145, 42, 20, 4, 16, 37, 58][if(n<18, n, (n-10)%8+10)] \\ M. F. Hasler, May 24 2009
(Magma) [6, 36, 45, 41, 17, 50, 25, 29, 85] cat &cat[[89, 145, 42, 20, 4, 16, 37, 58]: n in [0..17]]; // Vincenzo Librandi, Jan 29 2013
CROSSREFS
Cf. A003132 (the iterated map), A003621, A039943, A099645, A031176, A007770, A000216 (starting with 2), A000218 (starting with 3), A080709 (starting with 4), A000221 (starting with 5), A008462 (starting with 8), A008463 (starting with 9), A139566 (starting with 15), A122065 (starting with 74169). - M. F. Hasler, May 24 2009
Sequence in context: A348384 A328466 A232137 * A132633 A372945 A047792
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
An erroneous (duplicate) term deleted by M. F. Hasler, May 24 2009
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 17 15:57 EDT 2024. Contains 373463 sequences. (Running on oeis4.)