login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Numbers obtained by concatenating the squares of the digits of Catalan(n).
0

%I #9 Sep 08 2022 08:46:08

%S 1,1,4,25,116,164,194,16481,11690,1664364,136498136,2564496436,

%T 4064014,491648100,436491616160,81368116641625,9259254936490,

%U 148136161649810,164949369644900,149364943691810,362536161401640,41616363643649040,811166442536936160

%N Numbers obtained by concatenating the squares of the digits of Catalan(n).

%F a(n) = A048385(A000108(n)).

%e For n = 7, Catalan(7) = 429 and a(7) = 16481, which is the concatenation of the squares of the digits of 429. For n = 14, Catalan(14) = 2674440 and a(14) = 436491616160.

%t Table[FromDigits[Flatten[IntegerDigits/@(IntegerDigits[ CatalanNumber[ n]]^2)]],{n,0,30}] (* _Harvey P. Dale_, Sep 23 2020 *)

%o (Magma) [StringToInteger(&cat[IntegerToString(h): h in Reverse([i^2: i in Intseq(Catalan(n))])]): n in [0..30]];

%Y Cf. A000108, A048385.

%K nonn,base

%O 0,3

%A _Vincenzo Librandi_, Jul 05 2014