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 1-2 of 2 results.

A051818 Number of n-digit numbers with nonzero multiplicative digital root 7.

Original entry on oeis.org

1, 3, 14, 86, 666, 6418, 64079, 597445, 5116146, 40671872, 304752986, 2187716324, 15395364971, 110611591118, 866239098731, 7907500662596
Offset: 1

Views

Author

Dan Hoey, Dec 09 1999

Keywords

References

  • William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051809, A051827.

Formula

# { i : 10^(n-1) < i < 10^n and A051802(i)=7 }

A051827 Number of numbers below 10^n with nonzero multiplicative digital root 7.

Original entry on oeis.org

1, 4, 18, 104, 770, 7188, 71267, 668712, 5784858, 46456730, 351209716, 2538926040, 17934291011, 128545882129, 994784980860, 8902285643456
Offset: 1

Views

Author

Dan Hoey, Dec 09 1999

Keywords

Comments

Conjectured o(10^n)

References

  • William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051809, A051818.

Formula

# { i : 10^(n-1) < i < 10^n and A051802(i)=7 }
Showing 1-2 of 2 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.