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 1-3 of 3 results.

A048563 a(n+1) is next smallest nontrivial cube beginning with a(n), initial cube is 1.

Original entry on oeis.org

1, 125, 1259712, 12597128685582839, 1259712868558283970309163442200949867268191808152
Offset: 0

Views

Author

Patrick De Geest, May 15 1999

Keywords

Comments

Next terms are 144 and 431 digits long.

Links

Crossrefs

Cf. A048564.

A050647 a(n+1)^3 is next smallest cube ending with a(n)^3, initial term is 1.

Original entry on oeis.org

1, 11, 10011, 10000000010011, 10000000000000000000000000010000000010011
Offset: 1

Views

Author

Patrick De Geest, Jul 15 1999

Keywords

Comments

Frank Ellermann conjectures (Jun 11 2001) that if b(n) = 10^(3^n -1), i.e., 1, 100, 100000000, etc. then a(n) = concatenation b( n-2 ) || a( n-1 ) for n > 1.
a(6) is too large to include (contains 122 digits).

Crossrefs

Cf. A050646, A048564, A050641.

Formula

a(n) = Sum_{i=0..n-1} 10^((3^i-1)/2). - Max Alekseyev, Jan 07 2015

Extensions

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001, who remarks that a(6) = 10^121+a(5) = concat (10^80, a(5)) and a(7) = 10^364+a(6) = concat (10^242, a(6)), which supports Ellermann's conjecture

A050641 a(n+1)^3 is next smallest nontrivial cube containing a(n)^3 as a substring.

Original entry on oeis.org

1, 5, 45, 3632, 781253632
Offset: 1

Views

Author

Patrick De Geest, Jul 15 1999

Keywords

Comments

a(n+1) <= 10^m + a(n) where m is the number of digits of a(n)^3. - Chai Wah Wu, Mar 01 2019

Crossrefs

Cf. A050640, A048564, A050647.

Extensions

a(5) from Chai Wah Wu, Mar 01 2019
Showing 1-3 of 3 results.

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

Content is available under The OEIS End-User License Agreement.