A030671 Smallest extension of n-th prime which is a square.

25, 36, 529, 729, 1156, 1369, 1764, 196, 2304, 2916, 3136, 3721, 41209, 4356, 4761, 5329, 5929, 61009, 676, 71289, 7396, 7921, 83521, 89401, 97344, 101124, 103041, 107584, 109561, 113569, 12769, 131044, 137641, 13924, 149769, 15129

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n) = A030666(A000040(n)). - Robert Israel, Sep 05 2016

Example

For n=2, the second prime is 3, and 36 is the smallest square that begins with 3, so a(2) = 36. - Michael B. Porter, Sep 06 2016

Maple

A030666:= proc(x) local d;
for d from 1 do
  if ceil(sqrt(10^d*x)) <=  floor(sqrt(10^d*(x+1)-1)) then
     return ceil(sqrt(10^d*x))^2
fi
od
end proc:
seq(A030666(ithprime(i)), i=1..100); # Robert Israel, Sep 05 2016

Crossrefs

Cf. A000040, A030666, A030672.

Sequence in context: A205644 A077437 A077676 * A030681 A167363 A035383

Adjacent sequences: A030668 A030669 A030670 * A030672 A030673 A030674

Keyword

nonn,base

Author

Patrick De Geest

Extensions

Name edited by Robert Israel, Sep 06 2016

Status

approved