A285550 Numbers k such that the digits of k^2 are squares.

0, 1, 2, 3, 7, 10, 12, 20, 21, 30, 38, 70, 97, 100, 102, 107, 120, 138, 200, 201, 210, 212, 300, 380, 648, 700, 701, 951, 970, 997, 1000, 1002, 1007, 1020, 1049, 1070, 1200, 1380, 1393, 2000, 2001, 2010, 2100, 2120, 3000, 3148, 3153, 3451, 3743, 3747, 3800

Offset

1,3

Links

Giovanni Resta, Table of n, a(n) for n = 1..10000 (first 350 terms from Colin Barker)

Formula

a(n) = sqrt(A019544(n)). - Alois P. Heinz, Apr 21 2017

Mathematica

Sqrt[#]&/@Select[Range[0, 3800]^2, SubsetQ[{0, 1, 4, 9}, IntegerDigits[#]]&] (* Harvey P. Dale, Jun 14 2022 *)

Prog

(PARI) maxk=10000; L=List(); for(k=0, maxk, if(setminus(vecsort(digits(k^2), , 8), [0, 1, 4, 9]) == [], listput(L, k))); Vec(L)

Crossrefs

Cf. A000290, A019544, A046030.

Sequence in context: A102808 A215937 A140512 * A171863 A101956 A273064

Adjacent sequences: A285547 A285548 A285549 * A285551 A285552 A285553

Keyword

nonn,base

Author

Colin Barker, Apr 21 2017

Status

approved