login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A279857 Prime numbers p with the property that p is the sum of the squares of two or more distinct one-digit numbers. 0
5, 13, 17, 29, 37, 41, 53, 59, 61, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 163, 167, 179, 181, 191, 197, 199, 211, 223, 227, 229, 233, 239, 251, 269, 271, 281 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..43.

EXAMPLE

5 is in the sequence because 5 = 1^2 + 2^2.

13 is in the sequence because 13 = 2^2 + 3^2.

MATHEMATICA

list = {};

squares = Subsets[{1, 2, 3, 4, 5, 6, 7, 8, 9}]^2;

For[i=1, iā‰¤Length[squares], i++,

    If[PrimeQ[Total[squares[[i]] ]], AppendTo[list, Total[squares[[i]] ]]]];

Intersection[list] (* Robert Price, Dec 20 2016 *)

Select[Union[Total/@Subsets[Range[9]^2, {2, 9}]], PrimeQ] (* Harvey P. Dale, Jul 20 2020 *)

PROG

In the modeling language MiniZinc each prime number n belonging to the sequence produces a satisfactory solution for this model:

include "all_different.mzn";

int: n;

var 1..9: A;

var 1..9: B;

var 1..9: C;

var 1..9: D;

var 1..9: E;

var 1..9: F;

var 1..9: G;

var 1..9: H;

var 1..9: I;

var 0..1: nA; var 0..1: nB; var 0..1: nC; var 0..1: nD; var 0..1: nE; var 0..1: nF; var 0..1: nG; var 0..1: nH; var 0..1: nI;

solve satisfy;

constraint all_different([A, B, C, D, E, F, G, H, I]) /\

n=(A*A*nA+B*B*nB+C*C*nC+D*D*nD+E*E*nE+F*F*nF+G*G*nG+H*H*nH+I*I*nI)

CROSSREFS

Sequence in context: A208853 A265889 A191218 * A077426 A231754 A175768

Adjacent sequences:  A279854 A279855 A279856 * A279858 A279859 A279860

KEYWORD

nonn,base,fini,full

AUTHOR

Pierandrea Formusa, Dec 20 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 3 14:51 EST 2020. Contains 338906 sequences. (Running on oeis4.)