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

11, 44, 99, 1616, 2525, 3636, 4949, 6464, 8181, 100100, 121121, 144144, 169169, 196196, 225225, 256256, 289289, 324324, 361361, 400400, 441441, 484484, 529529, 576576, 625625, 676676, 729729, 784784, 841841, 900900, 961961, 10241024, 10891089, 11561156

Offset: 1

Author

Vincenzo Librandi, Jan 02 2015

Keywords

• nonn
• base
• easy

Links

• Aaron Toponce, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000290, A020338, A175605.

Programs

Magma

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

Maple

seq(n^2*(1+10^(1+ilog10(n^2))),n=1..100); # Robert Israel, Jan 02 2015

Mathematica

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

PARI

vector(100,n,eval(concat(Str(n^2),Str(n^2)))) \\ Derek Orr, Jan 02 2015

Formula

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