The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A015004 q-factorial numbers for q=5. 11
 1, 1, 6, 186, 29016, 22661496, 88515803376, 1728802155736656, 168827903320618878336, 82435457461295106532780416, 201258420458750640859769304304896, 2456767777551003294245070550498298923776, 149949204558598784020761783280669552547300269056 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..50 Index entries for sequences related to factorial numbers FORMULA a(n) = Product_{k=1..n} ((q^k - 1) / (q - 1)) where q = 5. a(0) = 1, a(n) = (5^n-1)*a(n-1)/4. - Vincenzo Librandi, Oct 25 2012 MATHEMATICA RecurrenceTable[{a[1]==1, a[n]==((5^n - 1)* a[n-1])/4}, a, {n, 15}] (* Vincenzo Librandi, Oct 25 2012 *) Table[QFactorial[n, 5], {n, 15}] (* Bruno Berselli, Aug 14 2013 *) PROG (Magma) [n le 1 select 1 else (5^n-1)*Self(n-1)/4: n in [1..15]]; // Vincenzo Librandi, Oct 25 2012 (PARI) a(n) = { my(q=5); prod(k=1, n, ((q^k - 1) / (q - 1))) } \\ Andrew Howroyd, Feb 18 2018 CROSSREFS Column q=5 of A069777. Cf. A015001, A015002, A015005, A015006, A015007, A015008, A015009, A015011. Sequence in context: A222335 A037298 A272467 * A324094 A129046 A222016 Adjacent sequences: A015001 A015002 A015003 * A015005 A015006 A015007 KEYWORD nonn,easy AUTHOR Olivier Gérard EXTENSIONS a(0)=1 prepended by Alois P. Heinz, Sep 08 2021 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 4 18:06 EST 2023. Contains 367563 sequences. (Running on oeis4.)