A371563 k=1..n times centrally deletable primes, or -1 if no such number exists.

101, 10009, 1000151, 100000609, 10000003787, 1000000210987, 100000003272019, 10000000005012649, 1000000000030109609, 100000000003242090733, 10000000000090420109609, 1000000000042957566399049, 100000000000040357566399049, 10000000000001990357566399049

Offset

1,1

Comments

Smallest prime number that remains prime when removing k times (1 <= k <= n) the one or two central digits, depending on whether the prime number has an odd or even number of digits.

Links

Jason Yuen, Table of n, a(n) for n = 1..89

Jason Yuen, Python program.

Example

a(2) = 10009. This is because 10009, 1009, and 19 are all prime numbers, and there is no smaller prime number that satisfies this property.

Crossrefs

Cf. A225082.

Sequence in context: A265172 A153500 A262861 * A164367 A263244 A368417

Adjacent sequences: A371560 A371561 A371562 * A371564 A371565 A371566

Keyword

nonn,base

Author

Jean-Marc Rebert, Mar 27 2024

Extensions

More terms from Jason Yuen, Apr 03 2024

Status

approved