OFFSET
1,2
COMMENTS
The first three are the only terms not divisible by 25 (and thus, not ending in 00 or 25). If 100 is a term, then the sequence should start with 3 more initial terms, namely (1, 4, 9, ...) - M. F. Hasler, Nov 01 2014
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..3000 (n = 4..403 from Christian N. K. Anderson and Kevin L. Schwartz)
EXAMPLE
225 = 15^2 becomes 25 = 5^2, 105625 = 325^2 becomes 5625 = 75^2.
MATHEMATICA
b^2 /. Flatten[Outer[Solve[a^2 + #2*10^#1 == b^2 && 0 <= a < Sqrt[10^#1] && Sqrt[#2*10^#1] <= b < Sqrt[10^(#1 + 1)], {a, b}, Integers] &, Range[0, 5], Range[9]], 2] (* Davin Park, Dec 30 2016 *)
PROG
(R)
no0<-function(s){ while(substr(s, 1, 1)=="0" & nchar(s)>1) s=substr(s, 2, nchar(s)); s};
issquare<-function(x) ifelse(as.bigz(x)<2, T, all(table(as.numeric(gmp::factorize(x)))%%2==0));
which(sapply(1:200, function(x) issquare(no0(substr(x^2, 2, ndig(x^2)))))>0)^2
(PARI) is_A225885(n)=issquare(n%10^(#Str(n)-1))&&issquare(n)&&n>9 \\ M. F. Hasler, Nov 01 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Kevin L. Schwartz and Christian N. K. Anderson, May 19 2013
EXTENSIONS
1,4,9 added (per M. F. Hasler's comment) by Chai Wah Wu, Nov 03 2014
STATUS
approved