A259489 - OEIS

%I #10 Sep 08 2022 08:46:13

%S 17,38,131,171,360,392,500,512,605,729,863,1031,1035,1481,1737,1994,

%T 2156,2268,2483,2513,2520,2732,2817,3011,3240,3384,3449,3710,3881,

%U 3923,4032,4100,4112,4145,4572,5193,5456,5598,5720,5832,5903,5924,7164,7388,7625,7631

%N Numbers n such that n plus the cube of sum of digits of n is a perfect square.

%C All the terms are congruent to 2 or 0 (mod 3).

%H K. D. Bajpai, <a href="/A259489/b259489.txt">Table of n, a(n) for n = 1..10000</a>

%e a(3) = 131: 131 + (1 + 3 + 1)^3 = 256 = 16^2.

%e a(4) = 171: 171 + (1 + 7 + 1)^3 = 900 = 30^2.

%t Select[Range[50000], IntegerQ[Sqrt[# +Plus@@(IntegerDigits[#])^3]]&]

%o (PARI) for(n = 1, 10^5, if(issquare(sumdigits(n)^3 + n), print1(n, ", ")))

%o (Magma) [ n: n in [1..10^4] |  IsSquare(&+Intseq(n)^3 + n) ] ;

%Y Cf. A007494, A052034, A061309, A091365, A091366.

%K nonn,base

%O 1,1

%A _K. D. Bajpai_, Jun 28 2015