

A098826


Palindromes that are 1 more than a prime and 1 less than a triangular number.


0



44, 252, 434, 464, 4004, 46664, 2005002, 49099094, 414878414, 431313134, 4370654560734, 200000050000002, 417622181226714, 202837977779738202, 2574289191919824752
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..15.


EXAMPLE

a(1) = 44 because 44 is the smallest (first) palindrome that is 1 more than a prime (43) and 1 less than a triangular number (45).


MATHEMATICA

Do[t = n(n + 1)/2  1; If[EvenQ[t], If[PrimeQ[t  1], If[t == FromDigits[ Reverse[ IntegerDigits[ t]]], Print[t]]]], {n, 10^9}] (* _Robert G. Wilson v, Nov 04 2004 *)
Select[Accumulate[Range[227*10^7]]1, PalindromeQ[#]&&PrimeQ[#1]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 02 2020 *)


CROSSREFS

Sequence in context: A233942 A122245 A031175 * A160284 A060836 A135182
Adjacent sequences: A098823 A098824 A098825 * A098827 A098828 A098829


KEYWORD

base,nonn


AUTHOR

Anonymous, Nov 02 2004


STATUS

approved



