OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10471 (terms n = 1..53 from Donovan Johnson, terms n = 54..1000 from Giovanni Resta)
Pante Stanica, Squares as concatenation of consecutive integers, Slides, West Coast Number Theory, Dec 17 2017.
EXAMPLE
428^2 = 183184, the concatenation of 183 and 184.
MATHEMATICA
t={}; Do[If[EvenQ[y=Length[x=IntegerDigits[n^2]]] && Differences[FromDigits/@Partition[x, y/2]]=={1}, AppendTo[t, n]], {n, 5.5*10^6}]; t (* Jayanta Basu, May 25 2013 *)
Sqrt[#]&/@(Select[FromDigits[Flatten[IntegerDigits/@#]]&/@ (Partition[ Range[735*10^6], 2, 1]), IntegerQ[Sqrt[#]]&]) (* The program takes a long time to run. *) (* Harvey P. Dale, Oct 10 2017 *)
PROG
(PARI) for(n=1, 10^9, t=eval(concat(Str(n), Str(n+1))); if(issquare(t, &s), print1(s, ", "))); /* Antonio Roldán and Joerg Arndt, Dec 31 2012 */
CROSSREFS
KEYWORD
nonn,base,nice
AUTHOR
EXTENSIONS
a(17) corrected by Donovan Johnson, Jan 03 2013
STATUS
approved