A033936 a(n+1) = a(n) + sum of squares of digits of a(n).

1, 2, 6, 42, 62, 102, 107, 157, 232, 249, 350, 384, 473, 547, 637, 731, 790, 920, 1005, 1031, 1042, 1063, 1109, 1192, 1279, 1414, 1448, 1545, 1612, 1654, 1732, 1795, 1951, 2059, 2169, 2291, 2381, 2459, 2585, 2703, 2765, 2879, 3077, 3184

Offset: 0

Author

Olivier Gorin (gorin(AT)roazhon.inra.fr)

Keywords

• nonn
• base

Comments

Orbit of 1 under iterations of A258881. - M. F. Hasler, Jul 23 2015

Examples

			After 1063, since 1^2 + 0^2 + 6^2 + 3^2 = 46 we get 1063+46 = 1109.
		

Links

• Robert Israel, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A258881, A003132, A076161.

Programs

Maple

A[0] := 1;
for n to 50 do
   A[n] := A[n-1]+add(t^2, t = convert(A[n-1], base, 10))
od:
seq(A[i],i=0..50); # Robert Israel, Feb 15 2018

Mathematica

NestList[#+Total[IntegerDigits[#]^2]&,1,45] (* Harvey P. Dale, Aug 14 2011 *)

Formula

a(n+1) = A258881(a(n)). a(n) = (A258881^n)(1). - M. F. Hasler, Jul 23 2015