A024517 Position of 2*n^2 in A000404 (sums of 2 nonzero squares).

1, 3, 7, 12, 18, 25, 34, 45, 56, 68, 82, 95, 112, 128, 146, 164, 183, 205, 227, 250, 275, 300, 325, 350, 382, 410, 440, 470, 503, 536, 569, 605, 642, 678, 717, 752, 794, 837, 878, 918, 963, 1007, 1054, 1101, 1147, 1196, 1246, 1293, 1348, 1401, 1452, 1506

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 03 2008, Table of n, a(n) for n = 1..130

Programs

PARI

i=0;for(n=1,1000000,f=factor(n);r=0;b=0;t=0;for(k=1,#f[,1],if(f[k,1]%4==1,r++,if(f[k,1]%4==3,b+=(f[k,2]%2),t=(f[k,2]%2)))); if(b==0 && (r>0 || t==1), i++; if(issquare(n/2),print1(i",")))) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 03 2008

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Mar 03 2008