A179633 Primes p such that p minus sum of integer of square root of its digits is a prime

3, 5, 7, 13, 31, 47, 103, 179, 197, 227, 269, 281, 317, 353, 359, 379, 383, 389, 439, 467, 499, 547, 577, 593, 619, 647, 739, 757, 829, 887, 953, 983, 1069, 1097, 1129, 1187, 1193, 1229, 1307, 1367, 1453, 1459, 1489, 1579, 1601, 1627, 1663, 1753, 1783, 1873

Offset

1,1

Links

Table of n, a(n) for n=1..50.

Example

n(5)=31 since 31-[int(sqrt(3))+int(sqrt(1))]=31-1-1=29 is prime.

Mathematica

Select[Prime[Range[300]], PrimeQ[#-Total[Floor/@Sqrt[IntegerDigits[#]]]]&] (* Harvey P. Dale, Aug 25 2013 *)

Crossrefs

Cf. A179632

Sequence in context: A089740 A191473 A290482 * A047933 A369433 A075557

Adjacent sequences: A179630 A179631 A179632 * A179634 A179635 A179636

Keyword

nonn,base

Author

Carmine Suriano, Jul 21 2010

Status

approved