OFFSET
1,2
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..358
FORMULA
a(n) = Product_{k=1..n} A115975(k).
EXAMPLE
A115975 begins with 1, 2, 3, 4, 5, 7, ..., so, a(1) = 1, a(2) = 1 * 2 = 2, a(3) = 1 * 2 * 3 = 6, ..., a(6) = 1 * 2 * 3 * 4 * 5 * 7 = 840.
MATHEMATICA
fib[lim_] := Module[{s = {}, f = 1, k = 2}, While[f <= lim, AppendTo[s, f]; k++; f = Fibonacci[k]]; s];
seq[max_] := Module[{s = {}, p = 2, e = 1, f = {}}, While[e > 0, e = Floor[Log[p, max]]; If[f == {}, f = fib[e], f = Select[f, # <= e &]]; s = Join[s, p^f]; p = NextPrime[p]]; FoldList[Times, 1, Sort[s]]]; seq[250]
PROG
(PARI) fib(lim) = {my(s = List(), f = 1, k = 2); while(f <= lim, listput(s, f); k++; f = fibonacci(k)); Vec(s); }
lista(pmax) = {my(s = [1], p = 2, e = 1, f = [], r = 1); while(e > 0, e = logint(pmax, p); if(#f == 0, f = fib(e), f = select(x -> x <= e, f)); s = concat(s, apply(x -> p^x, f)); p = nextprime(p+1)); s = vecsort(s); for(i = 1, #s, r *= s[i]; print1(r, ", ")); }
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Aug 09 2024
STATUS
approved