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.

A051812 Number of n-digit numbers with nonzero multiplicative digital root 1.

Original entry on oeis.org

1, 5, 24, 243, 3048, 35224, 374890, 3766188, 36537927, 348892847, 3315037530, 31399344551, 295789894509, 2769886220702, 25882768895688, 243033400452156
Offset: 1

Views

Author

Dan Hoey, Dec 09 1999

Keywords

Comments

Not counting zero as a one-digit number.

References

  • William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051803, A051821.

Formula

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

A051821 Number of numbers below 10^n with nonzero multiplicative digital root 1 (not counting 0).

Original entry on oeis.org

1, 6, 30, 273, 3321, 38545, 413435, 4179623, 40717550, 389610397, 3704647927, 35103992478, 330893886987, 3100780107689, 28983549003377, 272016949455533
Offset: 1

Views

Author

Dan Hoey, Dec 09 1999

Keywords

References

  • William Mayne, sci.math, Jun 15 1991

Crossrefs

Cf. A051802, A051803, A051812.

Formula

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

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

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