A027722 Numbers k such that k^2+k+7 is a palindrome.

0, 1, 17, 31, 177, 274, 280, 301, 313, 1777, 2764, 3001, 27259, 30001, 177237, 300001, 312208, 1762122, 3000001, 27515125, 30000001, 30122098, 300000001, 303758458, 2673533185, 2817818390, 3000000001, 3121001208, 26928832879, 28255878334, 30000000001

Offset

1,3

Links

Giovanni Resta, Table of n, a(n) for n = 1..45

P. De Geest, Palindromic Quasi_Over_Squares of the form n^2+(n+X)

Mathematica

palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; f[n_] := n^2 + n + 7; Select[Range[0, 10^5], palQ@ f@ # &] (* Giovanni Resta, Aug 29 2018 *)

Crossrefs

Cf. A027723, A027692, A027756, A005471, A027729, A027724.

Sequence in context: A085598 A163443 A339181 * A060342 A045700 A146800

Adjacent sequences: A027719 A027720 A027721 * A027723 A027724 A027725

Keyword

nonn,base

Author

Patrick De Geest

Extensions

More terms from Giovanni Resta, Aug 28 2018

Status

approved