A364198 - OEIS

%I #14 Jul 23 2023 02:08:39

%S 0,1,3,6,11,16,26,43,69,115,141,158,208,293,358,440,541,642,743,1117,

%T 1378,1612,1826,2052,2494,2856,3181,3703,4107,4862,5347,5924,6454,

%U 7645,8322,8999,9784,10941,12458,13580,14542,15839,16864,18309,19876,21696,23311,25408,28377,30314

%N Index of first occurrence of n in A364197.

%F a(n) ~ n^3/3  (conjectured).

%t s[0] = 0; s[n_] := s[n] = s[Abs[n - 1 - s[n - 1]^2]] + 1; TakeWhile[Flatten[FirstPosition[Array[s, 32000, 0] , #] & /@ Range[0, 50]] - 1 , NumberQ] (* _Amiram Eldar_, Jul 13 2023 *)

%o (Python)

%o a = [0]; [a.append(a[abs(n-a[n]**2)]+1) for n in range(1000)] # A364197

%o b = [a.index(n) for n in range(max(a)+1)] # A364198

%Y Cf. A364197.

%K nonn

%O 0,3

%A _Rok Cestnik_, Jul 13 2023