The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A057136 Palindromes whose square root is a palindrome. 7
 0, 1, 4, 9, 121, 484, 10201, 12321, 14641, 40804, 44944, 1002001, 1234321, 4008004, 100020001, 102030201, 104060401, 121242121, 123454321, 125686521, 400080004, 404090404, 10000200001, 10221412201, 12102420121, 12345654321, 40000800004 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Always contain an odd number of digits. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 (n=1..412 from N. J. A. Sloane based on R. J. Mathar's b-file for A057135) FORMULA a(n) = A057135(n)^2 EXAMPLE a(8) = 14641 since 14641 = 121^2 and 121 is also a palindrome MAPLE dmax:= 7: # to get all terms with up to dmax digits Res:= 0, 1, 2^2, 3^2, 11^2, 22^2: Po:= [[0], [1], [2], [3]]: Pe:= [[0, 0], [1, 1], [2, 2]]: for d from 1 to dmax do if d::odd then Po:= select(t -> add(s^2, s=t) < 10, [seq(seq([i, op(t), i], t=Po), i=0..2)]); Res:= Res, op(map(proc(p) if p[1] <> 0 then add(p[i]*10^(i-1), i=1..nops(p))^2 fi end proc, Po)) else Pe:= select(t -> add(s^2, s=t) < 10, [seq(seq([i, op(t), i], t=Pe), i=0..2)]); Res:= Res, op(map(proc(p) if p[1] <> 0 then add(p[i]*10^(i-1), i=1..nops(p))^2 fi end proc, Pe)) fi; od: Res; # Robert Israel, Jun 21 2017 MATHEMATICA Select[Range[0, 10^6], PalindromeQ[#] && PalindromeQ[#^2] &]^2 (* Robert Price, Apr 26 2019 *) CROSSREFS Cf. A000290, A002113, A002779, A057135 (the square roots). Sequence in context: A002779 A028817 A319483 * A048411 A225739 A065379 Adjacent sequences: A057133 A057134 A057135 * A057137 A057138 A057139 KEYWORD base,nonn AUTHOR Henry Bottomley, Aug 12 2000 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 21 18:37 EDT 2023. Contains 365503 sequences. (Running on oeis4.)