This site is supported by donations to The OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A046197 Fixed points for operation of repeatedly replacing a number with the sum of the cubes of its digits. 24
 0, 1, 153, 370, 371, 407 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Suppose n has d digits; then the sum of the cubes of its digits is <= 729d and n >= 10^(d-1). So d <= 5. It is now easy to check that the numbers shown are the only solutions. [Corrected by M. F. Hasler, Apr 12 2015] This is row n=3 of A252648. - M. F. Hasler, Apr 12 2015 REFERENCES J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 153, p. 50, Ellipses, Paris 2008. G. H. Hardy, A Mathematician's Apology, Cambridge, 1967. H. Lehning, "La migration des nombres vers le bonheur" in 'Tangente:L'aventure mathematique' pp. 27 No. 108 Jan-Feb 2006 Pole Paris. J. Shallit, Number theory and formal languages, in Emerging applications of number theory (Minneapolis, MN, 1996), 547-570, IMA Vol. Math. Appl., 109, Springer, New York, 1999. LINKS FORMULA A055012(a(n))=a(n); A165331(a(n))=0; subset of A165332. - Reinhard Zumkeller, Sep 17 2009 EXAMPLE 1^3 + 5^3 + 3^3 = 153. 3^3+7^3 +0^3 = 370. PROG (PARI) for(n=0, 10^5, A055012(n)==n&&print1(n", ")) \\ M. F. Hasler, Apr 12 2015 CROSSREFS Cf. A005188, A023052, A046156. Cf. A165330, A035504, A008585, A165333, A165334, A165335. Cf. A052455, A052464, A124068, A124069, A226970, A003321. Sequence in context: A194660 A159294 A066528 * A271730 A056733 A256748 Adjacent sequences:  A046194 A046195 A046196 * A046198 A046199 A046200 KEYWORD nonn,fini,full,base AUTHOR Richard C. Schroeppel 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 November 17 08:39 EST 2019. Contains 329217 sequences. (Running on oeis4.)