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A186086 Beastly primes (version 1): either 666 followed by 0's and a 1 or 7 at the right end or a palindrome with 666 in the center, 0's surrounding these digits, and 1 or 7 at both ends. 8
6661, 16661, 66601, 76667, 700666007, 6660000000001, 666000000000001, 700000666000007, 70000006660000007, 6660000000000000000000000007, 66600000000000000000000000007, 1000000000000066600000000000001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Differs from A131645 in that 26669, 46663, 56663, 66617, 66629, 66643, 66653, 66683, 66697, 96661, 96667, 106661, 106663, 106669, 116663, 146669, 166601, 166603, 166609, 166613, 166619, 166627, 166631, 166643, 166657, 166667, 166669, 166679, are not included here.

76667 is the largest beastly prime that does not contain the digit "0".

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..33

Chris Caldwell, The Prime Glossary, Beastly prime

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 6661

R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations (May 2001), p. 5

Tony Padilla and Brady Haran, The Most Evil Number, Numberphile video (2018)

Eric Weisstein's World of Mathematics, Beast Number

MATHEMATICA

e = 14; p = 666*10^n + 1; q = (10^(n + 2) + 666)*10^n + 1; Select[Union[Table[p, {n, 2*e}], Table[p + 6, {n, 2*e}], Table[q, {n, e}], Table[q + 6*10^(2*n + 2) + 6, {n, e}]], PrimeQ] (* Arkadiusz Wesolowski, Sep 21 2011 *)

Module[{nn=35, bp1, bp2, bp3, bp4}, bp1=FromDigits/@ Table[Join[PadRight[ {6, 6, 6}, n1, 0], {1}], {n1, 3, nn}]; bp2=FromDigits/@ Table[Join[ PadRight[ {6, 6, 6}, n2, 0], {7}], {n2, 3, nn}]; bp3=FromDigits/@ Table[Join[PadRight[ {1}, n3, 0], {6, 6, 6}, PadLeft[ {1}, n3, 0]], {n3, 1, nn/2}]; bp4=FromDigits/@ Table[Join[PadRight[{7}, n3, 0], {6, 6, 6}, PadLeft[ {7}, n3, 0]], {n3, 1, nn/2}]; Select[Sort[Join[bp1, bp2, bp3, bp4]], PrimeQ]] (* Harvey P. Dale, Jan 18 2017 *)

CROSSREFS

Cf. A046720, A051003, A131645, A164968, A196023, A138563, A186630, A186538, A156166, A186521.

Sequence in context: A119519 A233661 A131645 * A236733 A015310 A043516

Adjacent sequences:  A186083 A186084 A186085 * A186087 A186088 A186089

KEYWORD

nonn,base,dumb

AUTHOR

Arkadiusz Wesolowski, Feb 12 2011

EXTENSIONS

Edited by N. J. A. Sloane, Feb 12 2011

a(10)-a(12) from Charles R Greathouse IV, Feb 12 2011

STATUS

approved

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Last modified November 13 23:48 EST 2019. Contains 329106 sequences. (Running on oeis4.)