A027726 Numbers k such that k^2+k+9 is a palindrome.
0, 1, 9, 11, 13, 22, 30, 31, 138, 300, 304, 305, 331, 438, 969, 1141, 1413, 2367, 3000, 3144, 3881, 9854, 30000, 30605, 72062, 106801, 114141, 125206, 128348, 300000, 315165, 963304, 980560, 989154, 2378507, 3000000, 3040604, 3045679, 3152290, 3932806
Offset: 1
Links
- Giovanni Resta, Table of n, a(n) for n = 1..71
- P. De Geest, Palindromic Quasi_Over_Squares of the form n^2+(n+X)
Programs
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Mathematica
palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; f[n_] := n^2 + n + 9; Select[Range[0, 3*10^5], palQ@ f@ # &]
Extensions
More terms from Giovanni Resta, Aug 29 2018