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 1-6 of 6 results.

A050636 a(n+1) is next smallest square ending with a(n), initial term is 4.

Original entry on oeis.org

4, 64, 1764, 6041764, 96126041764, 8584885596126041764, 1094573934406914368584885596126041764, 164840278246153785356947805564195221094573934406914368584885596126041764
Offset: 1

Views

Author

Patrick De Geest, Jul 15 1999

Keywords

Examples

			a(6) = 8584885596126041764 = 2929997542^2.

Crossrefs

Cf. A050637, A048559, A050630, A061361.

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001

A050637 a(1) = 2; a(n+1)^2 is next smallest square ending with a(n)^2.

Original entry on oeis.org

2, 8, 42, 2458, 310042, 2929997542, 1046218875000310042, 406005268741864709999999997070002458, 50376698115810287966925579573179705000000000000000001046218875000310042
Offset: 1

Views

Author

Patrick De Geest, Jul 15 1999

Keywords

Crossrefs

Cf. A050636, A048560, A050631, A061361.
See A065789 for an essentially identical sequence.

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001

A061363 a(1) = 9; a(n) = least number such that the concatenation a(n)a(n-1)...a(2)a(1) is a square.

Original entry on oeis.org

9, 4, 18, 167, 2401, 4086461727, 14079962896835441528, 309880704108832516500624685064706000856, 4681896102766617737298881383797502847166028831212571921983062786215145771871779
Offset: 1

Views

Author

Amarnath Murthy, Apr 28 2001

Keywords

Examples

			a(3)a(2)a(1) = 1849 = 43^2, a(4)a(3)a(2)a(1) = 1671849 = 1293^2.

Crossrefs

Cf. A050638, A050639, A061359, A061361.

Extensions

Corrected by Larry Reeves (larryr(AT)acm.org), May 07 2001
More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001

A061491 a(1) = 1, a(n) = least number such that the concatenation a(n)a(n-1)...a(1) is a cube.

Original entry on oeis.org

1, 133, 100330363, 100000000300330000300660363, 100000000000000000000000000300000000300330000000000000300000000600660000300660363
Offset: 1

Views

Author

Amarnath Murthy, May 06 2001

Keywords

Examples

			a(1) = 1, a(2) = 133, a(2)a(1) = 1331 = 11^3.

Links

Crossrefs

Cf. A061359, A061361, A061363.

Programs

  • Maple
    f:= proc(n) local j; 10^(-3^(n-1)/2-1)*(add(10^(3^j/2),j=0..n-1)^3 - add(10^(3^j/2),j=0..n-2)^3) end proc:
seq(f(n),n=1..5); # Robert Israel, Jun 17 2024

Formula

a(n) = 10^(-3^(n-1)/2-1)*(Sum_{j=0..n-1}(10^(3^j/2))^3 - Sum_{j=0..n-2} (10^(3^j/2))^3). - Robert Israel, Jun 17 2024

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001
Corrected by Robert Israel, Jun 17 2024

A065790 a(1) = 64; 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

64, 17, 604, 9612, 85848855, 109457393440691436, 16484027824615378535694780556419522, 2537811713051483817817710620248313487995814710180147690293469081793581
Offset: 1

Views

Author

Klaus Brockhaus, Nov 19 2001

Keywords

Comments

a(n) = A061361(n+1) for n > 1.

Crossrefs

Cf. A061359, A061361, A065691, A065788, A065789.

A061492 a(1) = 8, a(n) = least number such that the concatenation a(n)a(n-1)...a(1) is a cube.

Original entry on oeis.org

8, 172, 1585108, 4768417578272894, 931322574615480750806365966798663150842303643
Offset: 1

Views

Author

Amarnath Murthy, May 06 2001

Keywords

Examples

			a(1) = 8, a(2) = 172, a(2)a(1) = 1728 = 12^3.

Crossrefs

Cf. A061359, A061361, A061363, A061491.

Extensions

Corrected and extended by Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001. Next element has 135 digits.
Showing 1-6 of 6 results.

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