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A253445 a(n) = concatenation of n^2 with itself. 2

%I #17 Sep 08 2022 08:46:10

%S 11,44,99,1616,2525,3636,4949,6464,8181,100100,121121,144144,169169,

%T 196196,225225,256256,289289,324324,361361,400400,441441,484484,

%U 529529,576576,625625,676676,729729,784784,841841,900900,961961,10241024,10891089,11561156

%N a(n) = concatenation of n^2 with itself.

%H Aaron Toponce, <a href="/A253445/b253445.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A020338(n^2) = n^2 * (1 + 10^(A004216(n^2)+1)).

%p seq(n^2*(1+10^(1+ilog10(n^2))),n=1..100); # _Robert Israel_, Jan 02 2015

%t Table[FromDigits[Join[IntegerDigits[n^2], IntegerDigits[n^2]]], {n, 40}]

%o (Magma) [Seqint(Intseq(n^2) cat Intseq(n^2)): n in [1..40]];

%o (PARI) vector(100,n,eval(concat(Str(n^2),Str(n^2)))) \\ _Derek Orr_, Jan 02 2015

%Y Cf. A000290, A020338, A175605.

%K nonn,base,easy

%O 1,1

%A _Vincenzo Librandi_, Jan 02 2015

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)