OFFSET
1,1
COMMENTS
If n is a member then so is 10*n. - Robert Israel, May 07 2020
LINKS
David A. Corneth, Table of n, a(n) for n = 1..10000 (first 5000 terms from Robert Israel)
EXAMPLE
a(7) = 1050 is a term because 1050^2 = 1102500; remove the first and last to get internal digits 10250, and 1050 is a subsequence of 10250. - Robert Israel, May 07 2020
MAPLE
filter:= n -> StringTools:-IsSubSequence(sprintf("%d", n), sprintf("%d", n^2)[2..-2]):
select(filter, [$10..30000]); # Robert Israel, May 07 2020
PROG
(Python)
from itertools import count, islice
def A046834_gen(startvalue=1): # generator of terms >= startvalue
for k in count(max(startvalue, 1)):
c = iter(str(k**2)[1:-1])
if all(map(lambda b:any(map(lambda a:a==b, c)), str(k))):
yield k
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved