1,1

Equivalently, prime numbers which cannot be written as sum of squares of primes (see A134622 for the proof). - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Nov 11 2007

Equivalently, prime numbers which cannot be written as sum of squares of 2 and 3 (see A134622 for the proof). - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Nov 11 2007

The sequence is finite, since numbers > 23 can be written as sums of squares >1 (see A078135). - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Nov 11 2007

Explicit representation as sum of squares of primes, or rather of squares of 2 and 3, for numbers m>23: we have m=c*2^2+d*3^2, where c:=((floor(m/4) - 2*(m mod 4))>=0, d:=m mod 4. For that, the finiteness of the sequence is proved. - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Nov 11 2007

Eric Weisstein's World of Mathematics, Square Number.

Index entries for sequences related to sums of squares

Cf. A000290, A078134, A078138, A000040, A078133.

Cf. A078135, A090677, A134622, A134754, A134755.

Sequence in context: A018146 A069749 A081889 this_sequence A120628 A039986 A079346

Adjacent sequences: A078136 A078137 A078138 this_sequence A078140 A078141 A078142

nonn,fini,full

Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Nov 19 2002