A065791 -id:A065791 - cp's OEIS frontend

A065792 a(1) = 9; for n > 1, a(n) is the square root of the smallest square > a(n-1)^2 with a(n-1)^2 forming its final digits.

9, 41, 1209, 469959, 176270001209, 6042408942999999530041, 16385871165869048127200000000000176270001209, 28444329561227422116741433513058707457037799999999999999999999993957591057000000469959

Offset: 1

Klaus Brockhaus, Nov 19 2001

a(n) = A050635(n+1) for n >= 1; a(n) = sqrt(A065791(n)).

Cf. A050635, A065690, A065791, A065793.

A065807 Squares with a smaller square as final digits.

Original entry on oeis.org

49, 64, 81, 100, 121, 144, 169, 225, 289, 324, 361, 400, 441, 484, 529, 625, 729, 784, 841, 900, 961, 1024, 1089, 1225, 1369, 1444, 1521, 1600, 1681, 1764, 1849, 1936, 2025, 2116, 2209, 2304, 2401, 2500, 2601, 2704, 2809, 2916, 3025, 3136, 3249, 3364

Offset: 1

Klaus Brockhaus, Nov 22 2001

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

A065808 gives the corresponding square roots.
Cf. A038678.
Cf. A065689, A050634, A050636, A050638, A065776, A061839, A065782, A065785, A065788, A065791.

ds[n_] := NestWhileList[FromDigits[Rest[IntegerDigits[#]]] &, n, # > 9 &]; Select[Range[4, 58]^2, Or @@ IntegerQ /@ Sqrt[Rest[ds[#]]] &] (* Jayanta Basu, Jul 10 2013 *)

a065807(m) = local(a, b, d, j, k, n); for(k=1, m, a=length(Str(n))-1; b=1; j=1; n=k^2; while(b, d=divrem(n, 10^j); if(d[1]>0&&issquare(d[2]), b=0; print1(n, ", "), if(j

isokend(n) = my(p=10); for(k=1, #Str(n)-1, if (issquare(n % p), return (1)); p*=10);
isok(n) = issquare(n) && isokend(n); \\ Michel Marcus, Mar 17 2020

Changed offset from 0 to 1 by Vincenzo Librandi, Sep 24 2013

A065793 a(1) = 81; for n > 1, a(n) is the smallest integer > 0 such that the concatenation a(n)a(n-1)...a(2)a(1) is a square.

Original entry on oeis.org

81, 16, 146, 22086, 31071113326, 365107058344463715696, 2684967738644586785227227090233956040549004, 809079884187716191997158821357206898310718837487307207657194711477350102495950972665

Offset: 1

Klaus Brockhaus, Nov 19 2001

a(n) = A061359(n+1) for n > 1.

Cf. A061359, A065691, A065791, A065792.

cp's OEIS Frontend

A065792 a(1) = 9; for n > 1, a(n) is the square root of the smallest square > a(n-1)^2 with a(n-1)^2 forming its final digits.

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A065807 Squares with a smaller square as final digits.

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A065793 a(1) = 81; for n > 1, a(n) is the smallest integer > 0 such that the concatenation a(n)a(n-1)...a(2)a(1) is a square.

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