

A260312


Palindromic beastly primes that begin and end with digit '1'.


1




OFFSET

1,1


COMMENTS

The next term a(4) contains 1017 digits, and is too large to include in data section.


LINKS

Table of n, a(n) for n=1..3.
Tony Padilla and Brady Haran, The Most Evil Number, Numberphile video (2018)


EXAMPLE

a(1) = 16661 is a palindromic prime that contains the beastly number '666' and begins and ends with digit 1.
a(2) = 1000000000000066600000000000001 is palindromic prime that contains the beastly number '666' and begins and ends with digit 1.


MAPLE

A260312:= n> ((1*10^(n + 2) + 666)*10^n + 1 ): select(isprime, [seq((A260312 (n), n=1..100))]);


MATHEMATICA

Select[Table[(1*10^(n + 2) + 666)*10^n + 1, {n, 1000}], PrimeQ]
Select[Table[FromDigits[Join[{1}, PadRight[{}, n, 0], {6, 6, 6}, PadRight[ {}, n, 0], {1}]], {n, 0, 50}], PrimeQ] (* Harvey P. Dale, Jul 09 2017 *)


PROG

(PARI) for(n=1, 500, k=((1*10^(n + 2) + 666)*10^n + 1 ); if(isprime(k), print1(k, ", ")));
(MAGMA) [k: n in [1..1000]  IsPrime(k) where k is ((1*10^(n + 2) + 666)*10^n + 1 )];


CROSSREFS

Cf. A046720, A051003, A131645, A186086.
Sequence in context: A196023 A108843 A232449 * A224572 A186311 A181098
Adjacent sequences: A260309 A260310 A260311 * A260313 A260314 A260315


KEYWORD

nonn,base,less


AUTHOR

K. D. Bajpai, Jul 22 2015


STATUS

approved



