login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Positive integers n such that n^3 divided by the digital sum of n is a cube.
4

%I #16 Oct 30 2014 07:06:16

%S 1,8,10,26,44,62,80,100,116,134,152,170,206,224,242,260,314,332,350,

%T 404,422,440,512,530,602,620,710,800,999,1000,1016,1034,1052,1070,

%U 1106,1124,1142,1160,1214,1232,1250,1304,1322,1340,1412,1430,1502,1520,1610

%N Positive integers n such that n^3 divided by the digital sum of n is a cube.

%H Colin Barker, <a href="/A236751/b236751.txt">Table of n, a(n) for n = 1..1000</a>

%e 152 is in the sequence because the digital sum of 152 is 8, and 152^3/8 = 438976 = 76^3.

%o (PARI)

%o s=[]; for(n=1, 3000, d=sumdigits(n); if(n^3%d==0 && ispower(n^3\d, 3), s=concat(s, n))); s

%Y Cf. A007953, A236748, A236749, A236750.

%K nonn,easy,base

%O 1,2

%A _Colin Barker_, Jan 30 2014