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 A052034 Primes such that the sum of the squares of their digits is also a prime. 17
 11, 23, 41, 61, 83, 101, 113, 131, 137, 173, 179, 191, 197, 199, 223, 229, 311, 313, 317, 331, 337, 353, 373, 379, 397, 401, 409, 443, 449, 461, 463, 467, 601, 641, 643, 647, 661, 683, 719, 733, 739, 773, 797, 829, 863, 883, 911, 919, 937, 971, 977, 991, 997, 1013 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p such that the sum of the squared digits of p is a prime q. For the values of q see A109181. REFERENCES Charles W. Trigg, Journal of Recreational Mathematics, Vol. 20(2), 1988. "Hands On Numbers Count", Personal Computer World, 1997, p. 290. Clifford A. Pickover, A Passion for Mathematics, John Wiley & Sons, Inc., 2005, p. 89. LINKS Zak Seidov, Table of n, a(n) for n = 1..10000 EXAMPLE p=23 is in the sequence because q = 2^2 + 3^2 = 13 is a prime. 9431 -> 9^2 + 4^2 + 3^2 + 1^2 = 107 (which is prime). MAPLE a:=proc(n) local nn, L: nn:=convert(n, base, 10): L:=nops(nn): if isprime(n)= true and isprime(add(nn[j]^2, j=1..L))=true then n else end if end proc: seq(a(n), n=1..1000); # Emeric Deutsch, Jan 08 2008 MATHEMATICA Select[Prime[Range], PrimeQ[Total[IntegerDigits[#]^2]]&]  (* Harvey P. Dale, Dec 19 2010 *) CROSSREFS Cf. A003132, A052035, A108662, A109181. Sequence in context: A094376 A086524 A060915 * A077041 A190797 A068842 Adjacent sequences:  A052031 A052032 A052033 * A052035 A052036 A052037 KEYWORD nonn,base AUTHOR Patrick De Geest, Dec 15 1999 EXTENSIONS Edited by N. J. A. Sloane, Dec 15 2007 and again on Dec 05 2008 at the suggestion of Zak Seidov STATUS approved

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Last modified July 15 22:48 EDT 2019. Contains 325061 sequences. (Running on oeis4.)