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A290934 a(n) equals the sum of the squares of the digits of A254958(n). 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified April 13 07:16 EDT 2021. Contains 342935 sequences. (Running on oeis4.)