A182251 - OEIS

%I #23 Feb 08 2023 12:49:18

%S 0,1,6,21,84,425,2586,18137,145096,1305873,13058830,143647141,

%T 1723765788,22408955257,313725373682,4705880605425,75294089686800,

%U 1279999524675617,23039991444161430,437759837439067189,8755196748781343780,183859131724408219737,4044900897936980834346

%N a(0) = 0, a(n) = (a(n-1) OR n) * n.

%H Harvey P. Dale, <a href="/A182251/b182251.txt">Table of n, a(n) for n = 0..449</a>

%F a(0) = 0, a(n) = (a(n-1) OR n) * n, where OR is the bitwise logical inclusive-OR operator.

%t a[0]=0; a[n_]:=n BitOr[a[n-1],n]; Array[a,23,0] (* _Stefano Spezia_, Apr 15 2022 *)

%t nxt[{n_,a_}]:={n+1,BitOr[a,n+1](n+1)}; NestList[nxt,{0,0},30][[All,2]] (* _Harvey P. Dale_, Feb 08 2023 *)

%o (Python)

%o a=0

%o for i in range(1,51):

%o   print(a)

%o   a |= i

%o   a *= i

%o (PARI) a(n) = if (n==0, 0, n*bitor(a(n-1), n)); \\ _Michel Marcus_, Apr 16 2022

%Y Cf. A080098.

%K base,nonn

%O 0,3

%A _Alex Ratushnyak_, Apr 20 2012