A055263 - OEIS

%I #14 Feb 19 2024 01:59:10

%S 0,1,3,6,1,6,3,1,9,9,10,3,6,10,6,3,10,9,9,10,3,6,10,6,3,10,9,9,10,12,

%T 6,10,6,12,10,9,9,10,12,6,10,6,12,10,9,9,10,12,6,10,6,12,10,9,9,10,12,

%U 15,10,15,12,10,9,9,10,12,15,10,15,12,10,9,9,10,12,15,10,15,12,10,9,9,10

%N a(n) = Sum of digits of (n + a(n-1)).

%C If n=0 or 8 mod 9, then a(n)=0 mod 9; if n=1, 4 or 7 mod 9, then a(n)=1 mod 9; if n=2 or 6 mod 9, then a(n)=3 mod 9; if n=3 or 5 mod 9, then a(n)=6 mod 9.

%H Harvey P. Dale, <a href="/A055263/b055263.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = A007953(A055262(n)) = A007953(n + a(n-1)).

%e a(13)=10 because a(12)=6, 13 + 6 = 19 and 1 + 9 = 10.

%t nxt[{n_,a_}]:={n+1,Total[IntegerDigits[n+a+1]]}; Transpose[NestList[nxt,{0,0},90]][[2]] (* _Harvey P. Dale_, Aug 11 2016 *)

%Y Cf. A055262, A055264.

%K base,easy,nonn

%O 0,3

%A _Henry Bottomley_, May 08 2000

%E More terms from _Paolo P. Lava_, Jul 31 2007