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A105814 a(n) = n^2 + (n concatenated with n). 0
12, 26, 42, 60, 80, 102, 126, 152, 180, 1110, 1232, 1356, 1482, 1610, 1740, 1872, 2006, 2142, 2280, 2420, 2562, 2706, 2852, 3000, 3150, 3302, 3456, 3612, 3770, 3930, 4092, 4256, 4422, 4590, 4760, 4932, 5106, 5282, 5460, 5640, 5822, 6006, 6192, 6380, 6570 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..45.

FORMULA

a(n) = n^2 + n*(1+10^(1+floor(log_10(n)))). - Robert Israel, Jul 30 2015

a(n) = n^2 + A020338(n). - Michel Marcus, Jul 31 2015

EXAMPLE

1 + 11 = 12, 4 + 22 = 26, 9 + 33 = 42, 16 + 44 = 60, ..., 100 + 1010 = 1110.

MAPLE

seq(n^2 + n*(1+10^(1+ilog10(n))), n=1..100); # Robert Israel, Jul 30 2015

MATHEMATICA

f[n_] := Block[{id = IntegerDigits[n]}, n^2 + FromDigits[ Join[id, id]]]; Table[ f[n], {n, 45}] (* Robert G. Wilson v, May 10 2005 *)

PROG

(PARI) vector(50, n, n^2 + eval(Str(n, n))) \\ Michel Marcus, Jul 31 2015

(MAGMA) [Seqint(Intseq(n) cat Intseq(n))+n^2: n in [1..50]] /* or */ [n^2+n*(1+10^(1+Floor(Log(n)/Log(10)))): n in [1..50]]; // Vincenzo Librandi, Jul 31 2015

CROSSREFS

Sequence in context: A054303 A184826 A119412 * A297427 A211115 A232936

Adjacent sequences:  A105811 A105812 A105813 * A105815 A105816 A105817

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini, May 05 2005

EXTENSIONS

More terms from Robert G. Wilson v, May 10 2005

STATUS

approved

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Last modified July 13 07:54 EDT 2020. Contains 335685 sequences. (Running on oeis4.)