A165333 Numbers that eventually reach the fixed point 370 under "x -> sum of cubes of digits of x" (see A055012).

7, 19, 34, 37, 43, 58, 67, 70, 73, 76, 85, 88, 91, 109, 118, 124, 139, 142, 145, 148, 154, 157, 166, 169, 175, 178, 181, 184, 187, 190, 193, 196, 214, 223, 226, 232, 241, 247, 259, 262, 268, 274, 277, 286, 295, 304, 307, 319, 322, 334, 340, 343, 346, 355, 358

Offset

1,1

Comments

A165330(a(n)) = 370;

Subsequence of A031179 and of A016777; a(n) mod 3 = 1.

Links

Table of n, a(n) for n=1..55.

Example

a(3)=34: 34 -> 3^3+4^3=91 -> 9^3+1=730 -> 7^3+3^3+0=370.

Mathematica

f[n_] := Plus@@(IntegerDigits[n]^3); Trajectory[n_] := Most[NestWhileList[f, n, UnsameQ , All]]; Select[Range[358], Last[Trajectory[#]] == 370&] (* Ant King, May 24 2013 *)

Crossrefs

Cf. A031179, A046197, A035504, A008585, A165334, A165335.

Sequence in context: A147503 A147465 A053591 * A154878 A124270 A298565

Adjacent sequences: A165330 A165331 A165332 * A165334 A165335 A165336

Keyword

base,nonn

Author

Reinhard Zumkeller, Sep 17 2009

Status

approved