A274932 Squares n = k^2 with the property that nextprime(k) is a substring of n.

529, 729, 6889, 12769, 162409, 644809, 851929, 1261129, 47969476, 64048009, 317837584, 1600240009, 2822053129, 24421563076, 40001200009, 84290347584, 107667328129, 145381301521, 160002400009, 437766166321, 788815751409

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..39 (all terms < 4*10^18)

Example

529 = 23^2, and nextprime(23) = 29 is a substring of 529, so 529 is a term.

Mathematica

Select[Range[2*10^6]^2, SequenceCount[IntegerDigits[#], IntegerDigits[ NextPrime[ Sqrt[ #]]]]>0&] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, Jul 13 2016 *)
Select[Range[2*10^6], {} != StringPosition @@ ToString /@ {#^2, NextPrime@ #} &]^2] (* Giovanni Resta, Jul 15 2016 *)

Crossrefs

Suggested by A052074.

Sequence in context: A339636 A181414 A020289 * A082409 A066742 A067475

Adjacent sequences: A274929 A274930 A274931 * A274933 A274934 A274935

Keyword

nonn,base

Author

Harvey P. Dale and N. J. A. Sloane, Jul 13 2016

Status

approved