A179631 Primes p such that p plus or minus the (sum of its digits and sum of squares of its digits) is a prime.

23, 229, 239, 283, 359, 563, 599, 683, 809, 829, 853, 883, 1181, 1217, 1787, 1811, 1847, 2069, 2411, 2693, 2939, 3329, 3583, 4547, 4871, 4877, 5059, 5099, 5171, 5683, 5693, 5717, 6203, 6269, 6353, 6829, 7487, 7541, 8629, 8747, 9239, 9283, 10181

Offset

1,1

Comments

Negative primes not permitted. - Harvey P. Dale, Sep 02 2015

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(3)=239 since 239+(2+3+9)+(2^2+3^2+9^2)=239+14+94=347 is prime AND 239-14-94=131 is prime.

Mathematica

sdQ[n_]:=Module[{sd=Total[IntegerDigits[n]]+Total[IntegerDigits[n]^2]}, sd<n&&AllTrue[n+{sd, -sd}, PrimeQ]]; Select[Prime[Range[1300]], sdQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 02 2015 *)

Crossrefs

Sequence in context: A206766 A142490 A051819 * A144248 A124336 A010829

Adjacent sequences: A179628 A179629 A179630 * A179632 A179633 A179634

Keyword

nonn,base

Author

Carmine Suriano, Jul 21 2010

Status

approved