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.

A202336 Number of digits in n^(n!).

Original entry on oeis.org

1, 1, 1, 3, 15, 84, 561, 4260, 36413, 346276, 3628801, 41569064, 516929544, 6936548425, 99917483647, 1537944393896, 25193549397053, 437655212248536, 8036723680196724, 155554110186062367, 3165278489148945082, 67553429525569109411, 1508884070229326953381
Offset: 0

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Author

Jacques ALARDET, Dec 17 2011

Keywords

Examples

			a(3) = 3 because 3^3! = 729 with 3 digits;
a(4) = 15 because 4^4! = 281474976710656 with 15 digits.
		

Crossrefs

Programs

  • Maple
    a:= proc(n) local h;
          Digits:= 1000;
          1+ `if`(n=0, 0, floor(n!*simplify(log[10](n))))
        end:
    seq(a(n), n=0..30); # Alois P. Heinz, Dec 17 2011
  • Mathematica
    Table[IntegerLength[n^n!],{n,0,10}] (* The program generates the first 11 terms of the sequence. *) (* Harvey P. Dale, Nov 19 2024 *)

Formula

a(n) = A055642(A053986(n)). - Michel Marcus, Aug 22 2013

Extensions

More terms from Alois P. Heinz, Dec 17 2011