A061118 Let s(n) be the sequence of squares (A000290). Then this sequence is given by s(1), s(2)s(1)s(3), s(4)s(2)s(1)s(3)s(5), ...

1, 419, 1641925, 36164192549, 643616419254981, 100643616419254981121, 144100643616419254981121169, 196144100643616419254981121169225, 256196144100643616419254981121169225289

Offset

1,2

Comments

a(n) is the concatenation of squares about 1 with even squares on the left and the odd squares on the right.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..50

Felice Russo, A Set of New Smarandache Functions, Sequences and Conjectures in Number Theory., Lupton, AZ: American Research Press, 2000.

Example

a(3) = 1641925, concatenation of 16, 4, 1, 9 and 25.

Maple

for n from 1 to 15 do for k from 2*(n-1) to 2 by -2 do printf(`%d`, k^2) od: for k from 1 to 2*n-1 by 2 do printf(`%d`, k^2) od: printf(`, `): od:

Mathematica

Table[Module[{sqs=Range[n]^2}, FromDigits[Flatten[IntegerDigits/@ Join[ Reverse[ Select[ sqs, EvenQ]], Select[sqs, OddQ]]]]], {n, 1, 21, 2}] (* Harvey P. Dale, Aug 13 2014 *)

Crossrefs

Sequence in context: A298699 A187218 A239253 * A097822 A069064 A024410

Adjacent sequences: A061115 A061116 A061117 * A061119 A061120 A061121

Keyword

nonn,base,less

Author

Amarnath Murthy, Apr 21 2001

Extensions

More terms from James A. Sellers, Apr 23 2001

Status

approved