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.

A220079 a(n) = 7^(n!).

Original entry on oeis.org

7, 7, 49, 117649, 191581231380566414401
Offset: 0

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Author

Vincenzo Librandi, Dec 16 2012

Keywords

Crossrefs

Programs

  • Magma
    [7^Factorial(n): n in [0..7]];
    
  • Mathematica
    Table[7^(n!), {n, 0, 7}]
  • Maxima
    makelist(7^(n!),n,0,5); /* Martin Ettl, Dec 27 2012 */

Formula

a(n) = a(n-1)^n, a(0) = 7.
a(n) = A000420(A000142(n)).

A385951 Number of digits in 5^(n!).

Original entry on oeis.org

1, 1, 2, 5, 17, 84, 504, 3523, 28183, 253643, 2536423, 27900646, 334807751, 4352500756, 60935010579, 914025158672, 14624402538737, 248614843158529, 4475067176853513, 85026276360216746, 1700525527204334919, 35711036071291033288, 785642793568402732327
Offset: 0

Views

Author

Vincenzo Librandi, Jul 27 2025

Keywords

Crossrefs

Subsequence of A210435.

Programs

  • Mathematica
    Array[Floor[#! Log10@5+1]&,22]

Formula

a(n) = A055642(A220078(n)).
Showing 1-2 of 2 results.