A290934 a(n) equals the sum of the squares of the digits of A254958(n).

1, 4, 9, 16, 25, 36, 49, 64, 81, 25, 25, 100, 100, 9, 81, 81, 9, 9, 49, 36, 49, 121, 121, 49, 49, 81, 81, 36, 36, 81, 81, 81, 144, 49, 121, 49, 81, 81, 121, 121, 121, 81, 121, 81, 81, 144, 144, 121, 121, 4, 36, 36, 100, 25, 25, 36, 100, 36, 100, 25, 49, 36, 36

Offset

1,2

Links

Jonathan Schwartz, Table of n, a(n) for n = 1..1000

Mathematica

Select[Map[Total, Select[Array[IntegerDigits, 1550], FreeQ[#, 0] &]^2], IntegerQ@ Sqrt@ # &] (* Michael De Vlieger, Aug 15 2017 *)

Prog

(Java) import java.util.ArrayList; public class Seq {public static void main(String[] args) {int l = 1000;
ArrayList<int> squares = new ArrayList<int>();
for (int i = 1; i <= l; i++) {squares.add((i * i)); }
int term = 1;
for (int n = 1; n < Integer.MAX_VALUE; n++) {
if (!(Integer.toString(n).contains("0")))
if (squares.contains(sum(n))){
int k = 0;
for(int i = 0; i<Integer.toString(n).length(); i++){k +=(Integer.valueOf(Character.toString(Integer.toString(n).charAt(i)))*Integer.valueOf(Character.toString(Integer.toString(n).charAt(i)))); }System.out.print(k + ", "); term++; }if(term>1000)break; }}
static int sum(int n) {int s = 0; String str = Integer.toString(n); for (int i = 0; i < str.length(); i++) {s += (Integer.valueOf(Character.toString(str.charAt(i)))*Integer.valueOf(Character.toString(str.charAt(i)))); }return s; }}
(PARI) lista(nn) = {for (n=1, nn, d = digits(n); if (vecmin(d) && issquare(s=sum(k=1, #d, d[k]^2)), print1(s, ", ")); ); } \\ Michel Marcus, Aug 28 2017

Crossrefs

Cf. A000290, A003132, A254958.

Sequence in context: A057147 A213630 A061205 * A048387 A035121 A080151

Adjacent sequences: A290931 A290932 A290933 * A290935 A290936 A290937

Keyword

nonn,base

Author

Jonathan Schwartz, Aug 14 2017

Status

approved