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A330414 Cyclops primes that become a cube when the middle "0" is removed. 1
68059, 1170649, 4560533, 7530571, 136501919, 158103251, 173703979, 212503933, 226605187, 356101289, 362604691, 382702753, 439806977, 518905117, 811802737, 954403993, 19484041249, 19956016979, 22635071297, 24658046551, 27263097773, 34635012697, 35326042667, 37166072149, 39668022287, 41499095543, 44839062449 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000 (first 60 terms from Rodolfo Ruiz-Huidobro)

EXAMPLE

a(1) = 68059 because 6859 = 19^3 is the first cube that results from the removal of the 0 digit from a cyclops prime.

136501919 is a term because 13651919 is 239^3.

MAPLE

count:= 0: Res:= NULL:

for d from 2 to 6 do

  for n from ceil(10^((2*d-1)/3)) to floor((10^(2*d)-1)^(1/3)) do

    L:=convert(n^3, base, 10);

    if member(0, L) then next fi;

    a:= n^3 mod 10^d;

    p:= 10*(n^3-a)+a;

    if isprime(p) then

      count:= count+1; Res:= Res, p;

    fi

od od:

Res; # Robert Israel, Dec 24 2019

PROG

(PARI) seq(n)={my(i=0, L=List()); while(#L<n, i++; my(v=digits(i^3), k=#v\2); if(#v==2*k && !#select(t->t==0, v), my(m=fromdigits(concat([v[1..k], 0, v[k+1..#v]]))); if(isprime(m), listput(L, m)))); Vec(L)} \\ Andrew Howroyd, Dec 20 2019

CROSSREFS

Cf. A329737, A134809, A016755.

Sequence in context: A234655 A104948 A237807 * A237389 A234662 A250924

Adjacent sequences:  A330411 A330412 A330413 * A330415 A330416 A330417

KEYWORD

nonn,base,easy

AUTHOR

Rodolfo Ruiz-Huidobro, Dec 14 2019

STATUS

approved

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Last modified September 29 10:30 EDT 2022. Contains 357088 sequences. (Running on oeis4.)