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A046950 Square elements of A046949. 0
1, 25, 49, 169, 625, 1369, 3025, 7921, 18769, 37249, 208849, 3485689, 4950625, 7756225, 225150025, 48195616225, 264353307409, 453673643809, 1278932548201 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..18.

MATHEMATICA

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

PROG

(PARI) B=1; 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), print("B is square ", B)))

CROSSREFS

Sequence in context: A137659 A020325 A108604 * A146641 A171590 A322434

Adjacent sequences:  A046947 A046948 A046949 * A046951 A046952 A046953

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Jason Earls, Jul 21 2001

STATUS

approved

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Last modified April 10 15:47 EDT 2021. Contains 342845 sequences. (Running on oeis4.)