login
A207373
Numbers whose square is the product of a number and its reverse.
2
252, 403, 504, 660, 816, 2772, 3267, 4356, 20502, 22932, 23632, 25452, 26962, 27972, 31003, 32967, 35143, 41004, 43956, 45864, 48384, 48616, 55242, 58422, 66976, 75525, 225522, 252252, 259952, 279972, 329967, 341033, 403403, 439956, 451044, 504504, 619916
OFFSET
1,1
COMMENTS
Number and its reverse must have the same number of digits.
Number squared cannot be a palindrome. - Harvey P. Dale, Mar 12 2017
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..1169 (terms < 10^12, first 90 terms from Harvey P. Dale)
EXAMPLE
35143^2 = 96721*12769.
MATHEMATICA
nir[n_]:=If[PalindromeQ[n]||Divisible[n, 10], 0, n IntegerReverse[n]]; Sqrt[#] &/@ Select[Array[nir, 500000], #!=0&&IntegerQ[Sqrt[#]]&]//Union (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 12 2017 *)
CROSSREFS
Cf. A076750.
Sequence in context: A066695 A372755 A104396 * A072443 A129623 A062904
KEYWORD
nonn,base
AUTHOR
Carmine Suriano, Feb 17 2012
STATUS
approved