A053061 a(n) is the decimal concatenation of n and n^2.

11, 24, 39, 416, 525, 636, 749, 864, 981, 10100, 11121, 12144, 13169, 14196, 15225, 16256, 17289, 18324, 19361, 20400, 21441, 22484, 23529, 24576, 25625, 26676, 27729, 28784, 29841, 30900, 31961, 321024, 331089, 341156, 351225, 361296, 371369, 381444, 391521

Offset: 1

Author

Felice Russo, Feb 25 2000

Keywords

• easy
• nonn
• base

References

• Felice Russo, A set of new Smarandache functions, sequences and conjectures in number theory, American Research Press 2000

Links

• Georg Fischer, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A020338, A055436, A061086, A175605, A253445.

Programs

Magma

[Seqint(Intseq(n^2) cat Intseq(n)): n in [1..40]]; // Vincenzo Librandi, Jan 03 2015

Mathematica

Table[FromDigits[Join[IntegerDigits[n],IntegerDigits[n^2]]],{n,40}] (* Harvey P. Dale, May 24 2012 *)

Python

def a(n): return int(str(n) + str(n*n))
print([a(n) for n in range(1, 40)]) # Michael S. Branicky, Nov 24 2021

Formula

a(n) = n*(10^floor(2*log_10(n) + 1) + n). - Henry Bottomley, May 18 2000

a(n) ~ n^3. - Charles R Greathouse IV, Sep 19 2012

Extensions

More terms from James Sellers, Feb 28 2000