login
A165459
Primes p such that the sum of the digits of p^2 is 16.
5
13, 23, 31, 41, 59, 103, 131, 139, 211, 229, 239, 347, 401, 491, 499, 571, 751, 1021, 1201, 1229, 1453, 1489, 1499, 1741, 2003, 2011, 3001, 3821, 4001, 4639, 4649, 5701, 7079, 8951, 10111, 10247, 10301, 10499, 14251, 14639, 16249, 17321, 19751, 20011
OFFSET
1,1
LINKS
FORMULA
{A000040(i) : A123157(i) = 16}. [R. J. Mathar, Nov 09 2009]
EXAMPLE
31 is in the sequence because 31^2=961 and 9+6+1=16;
1489 is in the sequence because 1489^2=2217121 and 2+2+1+7+1+2+1=16;
3001 is in the sequence because 3001^2=9006001 and 9+0+0+6+0+0+1=16.
MAPLE
A007953 := proc(n) local d ; add(d, d=convert(n, base, 10)) ; end proc: A165459 := proc(n) local a ; if n = 1 then 13; else a := nextprime( procname(n-1)) ; while A007953(a^2) <> 16 do a := nextprime(a) ; end do ; return a ; end if; end proc: seq(A165459(n), n=1..50) ; # R. J. Mathar, Nov 09 2009
MATHEMATICA
Select[Prime[Range[3000]], Total[IntegerDigits[#^2]]==16 &] (* Vincenzo Librandi, Jun 24 2013 *)
PROG
(Magma) [p: p in PrimesUpTo(3*10^4) | &+Intseq(p^2) eq 16]; // Bruno Berselli, Jun 24 2013
CROSSREFS
Sequence in context: A296806 A143788 A351686 * A108794 A272721 A089777
KEYWORD
nonn,less,base
AUTHOR
Vincenzo Librandi, Sep 20 2009
EXTENSIONS
Edited by N. J. A. Sloane, Sep 25 2009
347 inserted, more terms added by R. J. Mathar, Nov 09 2009
STATUS
approved