A046950 Square elements of A046949.

1, 25, 49, 169, 625, 1369, 3025, 7921, 18769, 37249, 208849, 3485689, 4950625, 7756225, 225150025, 48195616225, 264353307409, 453673643809, 1278932548201, 5225490897028249, 6290436331177441, 16712972707067569

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• nice
• more

Crossrefs

Cf. A046949.

Programs

Mathematica

Join[{1}, Table[ 24*Sum[ d*Mod[d, 2], {d, Divisors[n]}], {n, 1, 10^6}]] // Accumulate // Select[#, IntegerQ[Sqrt[#]] &] & (* Jean-François Alcover, Jul 02 2013 *)

PARI

B=1; print1(B, ", "); for (n=1,200000,t1=divisors(2*n); t2=0; for (i=1, length(t1), if( t1[ i ]%4 <> 0, t2=t2+t1[ i ])); B=B+8*t2; if (issquare(B), print1(B, ", ")))

Extensions

a(17)-a(18) from Jason Earls, Jul 21 2001

a(19)-a(21) from Sean A. Irvine, May 07 2021