OFFSET
1,1
LINKS
G. J. Simmons, Palindromic powers, J. Rec. Math., 3 (No. 2, 1970), 93-98. [Annotated scanned copy] See page 95.
FORMULA
Equals A263619(2n)-1.
MATHEMATICA
Table[Length[Select[Range[1, Floor[Sqrt[10^(2 n)]]], PalindromeQ[#^2] &]], {n, 6}] (* Robert Price, Apr 26 2019 *)
PROG
(Python)
def ispal(n): s = str(n); return s == s[::-1]
def a(n):
c, k, kk = 0, 1, 1
while kk < 10**(2*n): c, k, kk = c + (ispal(kk)), k+1, kk + 2*k + 1
return c
print([a(n) for n in range(1, 8)]) # Michael S. Branicky, Mar 06 2021
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
N. J. A. Sloane, Oct 23 2015
EXTENSIONS
a(7)-a(10) from Chai Wah Wu, Oct 25 2015
More terms using A263618 from Chai Wah Wu, Jun 14 2024
STATUS
approved