A046896 Square elements of A046895.

1, 9, 3969, 5041, 9409, 89401, 35010889, 478953225, 741091729, 282110761881, 370672751241, 1930979822409, 5548799536921, 6445713623281, 81193957971361, 1368832987094049, 1733317430330641, 2020590872666289, 3499458009751089, 3957304111109449, 216035761313239729

Offset

0,2

Comments

No other terms in first 200000 terms of A046895, though sequence is believed to be infinite.

No other terms in first 8000000 terms of A046895. - T. D. Noe, Mar 11 2009

Links

Table of n, a(n) for n=0..20.

Mathematica

s = 0; Reap[ Do[s = s + SquaresR[4, n]; If[IntegerQ[Sqrt[s]], Print[{n, s}]; Sow[s]], {n, 0, 5*10^6}]][[2, 1]] (* Jean-François Alcover, Jul 02 2012 *)

Prog

(Python)
from itertools import count, islice
from sympy import divisor_sigma
from sympy.ntheory.primetest import is_square
def A046896_gen(): # generator of terms
    c = 0
    for n in count(0):
        c += int(divisor_sigma(n)<<3 if n&1 else 3*divisor_sigma(n>>(~n&n-1).bit_length())<<3 if n else 1)
        if is_square(c):
            yield c
A046896_list = list(islice(A046896_gen(), 6)) # Chai Wah Wu, Feb 21 2026

Crossrefs

Cf. A046895.

Sequence in context: A162013 A222948 A281876 * A036516 A024126 A163018

Adjacent sequences: A046893 A046894 A046895 * A046897 A046898 A046899

Keyword

nonn,nice

Author

Vinay Vaishampayan and N. J. A. Sloane

Extensions

Extended by T. D. Noe, Mar 11 2009

a(15)-a(19) from Chai Wah Wu, Feb 22 2026

a(20) from Chai Wah Wu, Mar 03 2026

Status

approved