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A285550
Numbers k such that the digits of k^2 are squares.
5
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
KEYWORD
nonn,base
AUTHOR
Colin Barker, Apr 21 2017
STATUS
approved