A355591 a(n) = (product of the first n odd primes) - (sum of the first n odd primes).
1, 0, 7, 90, 1129, 14976, 255199, 4849770, 111546337, 3234846488, 100280244907, 3710369067210, 152125131763369, 6541380665834736, 307444891294245379, 16294579238595021986, 961380175077106319097, 58644190679703485491136, 3929160775540133527938979
Offset: 0
Keywords
Examples
a(4) = (3*5*7*11) - (3+5+7+11) = 1129.
Links
- Robert Israel, Table of n, a(n) for n = 0..348
Programs
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Maple
a:= n-> (l-> mul(i,i=l)-add(i,i=l))([ithprime(i)$i=2..n+1]): seq(a(n), n=0..20); # Alois P. Heinz, Jul 12 2022
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Mathematica
FoldList[Times, 1, p = Prime[Range[2, 20]]] - Prepend[Accumulate[p], 0] (* Amiram Eldar, Jul 14 2022 *)
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PARI
a(n) = my(vp=primes(n+1)); vecprod(vp)/2 - vecsum(vp) + 2; \\ Michel Marcus, Jul 12 2022
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Python
from itertools import count, islice from sympy import nextprime def agen(): p, s, primen = 1, 0, 2 while True: yield p - s; primen = nextprime(primen); p *= primen; s += primen print(list(islice(agen(), 19))) # Michael S. Branicky, Jul 12 2022
Extensions
More terms from Michael S. Branicky, Jul 12 2022
Comments