A027725 Palindromes of form k^2 + k + 8.

8, 878, 41014, 81518, 8558558, 8617168, 415242514, 874414478, 88279997288, 8035521255308, 8053537353508, 8942435342498, 8984014104898, 82375268486257328, 8563985811185893658, 41023644811311844632014, 87279499176567199497278, 462070049490878094940070264, 467190356216898612653091764

Offset: 1

Author

Patrick De Geest

Keywords

• nonn
• base

Comments

Palindromes h such that 4*h - 31 is a square. - Bruno Berselli, Aug 29 2018

Links

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

Crossrefs

Cf. A027724, A027693, A027723, A027727.

Programs

Mathematica

palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; f[n_] := n^2 + n + 8; Select[f@ Range[0, 3*10^5], palQ] (* Giovanni Resta, Aug 29 2018 *)

Extensions

a(14)-a(19) from Giovanni Resta, Aug 29 2018