cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-9 of 9 results.

A065689 a(1) = 0; for n > 1, a(n) is the smallest square > a(n-1) with a(n-1) forming its final digits.

Original entry on oeis.org

0, 100, 8100, 168100, 146168100, 22086146168100, 3107111332622086146168100, 3651070583444637156963107111332622086146168100, 26849677386445867852272270902339560405490043651070583444637156963107111332622086146168100
Offset: 1

Views

Author

Klaus Brockhaus, Nov 17 2001

Keywords

Comments

a(n) = 100*A050634(n-1) for n > 1.

Crossrefs

Cf. A050634, A050635, A061359, A065690, A065691.

A065691 a(1) = 0; 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

0, 10, 8, 16, 146, 22086, 31071113326, 365107058344463715696, 2684967738644586785227227090233956040549004, 809079884187716191997158821357206898310718837487307207657194711477350102495950972665
Offset: 1

Views

Author

Klaus Brockhaus, Nov 17 2001

Keywords

Comments

a(n) = A061359(n-1) for n > 2.

Crossrefs

Cf. A050634, A050635, A061359, A065689, A065690.

A065789 a(1) = 8; 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.

Original entry on oeis.org

8, 42, 2458, 310042, 2929997542, 1046218875000310042, 406005268741864709999999997070002458, 50376698115810287966925579573179705000000000000000001046218875000310042
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Comments

a(n) = A050637(n+1) for n >= 1; a(n) = sqrt(A065788(n)).
Essentially the same as A050637. - Zak Seidov, Mar 12 2012

Crossrefs

Cf. A050635, A050637, A065690, A065788, A065790.

A065777 a(1) = 4; 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.

Original entry on oeis.org

4, 46, 2454, 314954, 4492502454, 8866500849999685046, 4716968811408150949999999995507497546, 8302295225692406203256091732061577875000000000000000008866500849999685046
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Crossrefs

Cf. A050635, A065690, A065776, A065778.

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Dec 18 2001

A065780 a(1) = 5; 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.

Original entry on oeis.org

5, 15, 35, 285, 4035, 2660285, 40530004035, 478354453999997339715, 31246194523464509984000000000040530004035, 8209490213224904365731763888026434805200000000000000000000478354453999997339715
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Crossrefs

Cf. A050635, A065690, A061839, A065781.

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Dec 18 2001

A065783 a(1) = 6; 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.

Original entry on oeis.org

6, 44, 2456, 1247544, 214842502456, 29945373749998752456, 7489739829907193749999999785157497544, 2122105977711165946126545050684497624999999999999999970054626250001247544
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Crossrefs

Cf. A050635, A065690, A065782, A065784.

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Dec 18 2001

A065786 a(1) = 7; 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.

Original entry on oeis.org

7, 43, 1293, 154957, 20214998707, 118659019449999845043, 5566692951015284052000000000020214998707, 21637689578064053873124753714430240419600000000000000000000118659019449999845043
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Comments

a(n) = A050639(n+1) for n >= 1.

Crossrefs

Cf. A050635, A050639, A065690, A065785, A065787.

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.

Original entry on oeis.org

9, 41, 1209, 469959, 176270001209, 6042408942999999530041, 16385871165869048127200000000000176270001209, 28444329561227422116741433513058707457037799999999999999999999993957591057000000469959
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Comments

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

Crossrefs

Cf. A050635, A065690, A065791, A065793.

A065808 Square of n has a smaller square as its final digits.

Original entry on oeis.org

7, 8, 9, 10, 11, 12, 13, 15, 17, 18, 19, 20, 21, 22, 23, 25, 27, 28, 29, 30, 31, 32, 33, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 67, 68, 69, 70, 71, 72, 73, 75, 77, 78, 79, 80, 81, 82, 83, 85, 87, 88
Offset: 1

Views

Author

Klaus Brockhaus, Nov 22 2001

Keywords

Comments

Includes all n >= 7 not == 4 or 6 (mod 10). - Robert Israel, Oct 24 2017

Links

Crossrefs

A065807 gives the corresponding squares.
Cf. A065690, A050635, A050637, A050639, A065777, A065780, A065783, A065786, A065789, A065792.

Programs

  • Maple
    filter:= n ->
  ormap(t -> issqr(n^2 mod 10^t), [$1..ilog10(n^2)]):
select(filter, [$1..100]); # Robert Israel, Oct 24 2017
  • Mathematica
    ds[n_] := NestWhileList[FromDigits[Rest[IntegerDigits[#]]] &, n, # > 9 &]; Select[Range[4, 88], Or @@ IntegerQ /@ Sqrt[Rest[ds[#^2]]] &] (* Jayanta Basu, Jul 10 2013 *)
  • PARI
    a065808(m) = local(k, a, b, d, j, n, r); 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; issquare(n, &r); print1(r, ","), if(j

Extensions

Offset changed to 1 by Robert Israel, Oct 24 2017
Showing 1-9 of 9 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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