A206528 5^n concatenated with itself.

11, 55, 2525, 125125, 625625, 31253125, 1562515625, 7812578125, 390625390625, 19531251953125, 97656259765625, 4882812548828125, 244140625244140625, 12207031251220703125, 61035156256103515625, 3051757812530517578125, 152587890625152587890625

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Formula

a(n) = A020338(5^n).

Example

a(1)=55 because 5^1 concatenated with 5^1 is 55.

Mathematica

Table[FromDigits[Join[IntegerDigits[5^n], IntegerDigits[5^n]]], {n, 0, 20}]

Prog

(Magma) [Seqint(Intseq(5^n) cat Intseq(5^n)): n in [0..20]];

Crossrefs

Cf. A000351, A178664, A206527.

Sequence in context: A165791 A032166 A218000 * A259193 A099532 A041226

Adjacent sequences: A206525 A206526 A206527 * A206529 A206530 A206531

Keyword

nonn,base,easy

Author

Vincenzo Librandi, Mar 17 2012

Status

approved