|
|
A350758
|
|
Sum of all (j+1)-th products of (n-2j) successive primes for j=0..floor(n/2).
|
|
2
|
|
|
1, 2, 7, 33, 226, 2420, 31221, 525917, 9960028, 228028812, 6582873441, 203832844657, 7522104144920, 307994276065974, 13236129969377405, 621482119947376921, 32898794005805573210, 1939157848567313376490, 118255213619653849652599, 7917287291057332412711339
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = Sum_{j=0..floor(n/2)} A096334(n-j,j).
|
|
EXAMPLE
|
a(0) = 1.
a(1) = 2.
a(2) = 2*3 + 1 = 7.
a(3) = 2*3*5 + 3 = 33.
a(4) = 2*3*5*7 + 3*5 + 1 = 226.
a(5) = 2*3*5*7*11 + 3*5*7 + 5 = 2420.
|
|
MAPLE
|
b:= proc(n, k) option remember;
`if`(n=k, 1, b(n-1, k)*ithprime(n))
end:
a:= n-> add(b(n-j, j), j=0..n/2):
seq(a(n), n=0..20);
|
|
MATHEMATICA
|
b[n_, k_] := b[n, k] = If[n == k, 1, b[n - 1, k]*Prime[n]];
a[n_] := Sum[b[n - j, j], {j, 0, n/2}];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|