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

31 is in the sequence since 31 - floor(sqrt(3)) - floor(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: A391948 A191473 A290482 * A047933 A369433 A075557

Adjacent sequences: A179630 A179631 A179632 * A179634 A179635 A179636

Keyword

nonn,base

Author

Carmine Suriano, Jul 21 2010

Status

approved