This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A115026 Limiting value of n under iteration of "sum of the digits raised to the power of the number of digits of n" (A101337). 0
 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 5, 1, 370, 370, 370, 370, 370, 1, 4, 5, 8, 1, 4, 370, 370, 370, 1, 370, 9, 1, 1, 370, 370, 370, 370, 370, 370, 370, 370, 370, 4, 370, 1, 370, 370, 370, 370, 1, 370, 370, 370, 370, 370, 370, 370, 370, 370, 160, 370, 370, 370, 370, 370, 370 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Iterate A101337 starting at n until reaching a constant value (like 370) or a cycle (like 160, 217, 352, 160...). In the latter case a(n) takes the smallest value in the cycle (e.g. a(59) = 160). Since k*9^k < 10^k for all k>34, then each number n is guaranteed to yield a smaller number a(n) if n > 10^34, so every number reaches a constant or a cycle under this sequence. LINKS EXAMPLE E.g. a(89)=370 since: 89 (2 digits): 8^2 + 9^2 = 145 145 (3 digits): 1^3 + 4^3 + 5^3 = 190 190 (3 digits): 1^3 + 9^3 + 0^3 = 730 730 (3 digits): 7^3 + 3^3 + 0^3 = 370 370 (3 digits): 3^3 + 7^3 + 0^3 = 370...etc So a(89) = 370 since 370 is a constant value under this series. CROSSREFS Cf. A101337. Sequence in context: A209685 A114570 A247796 * A101337 A135208 A259043 Adjacent sequences:  A115023 A115024 A115025 * A115027 A115028 A115029 KEYWORD nonn,base AUTHOR Sergio Pimentel, Feb 24 2006 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.