OFFSET
0,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..400
Peter Luschny, An old operation on sequences: the Seidel transform.
J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon transform, J. Combin. Theory, 17A (1996) 44-54 (Abstract, pdf, ps).
N. J. A. Sloane, Transforms.
Wikipedia, Boustrophedon transform.
FORMULA
E.g.f.: (sec(x) + tan(x))*(1 + Sum_{k>=1} prime(k)*x^k/k!). - Ilya Gutkovskiy, Apr 23 2019
MATHEMATICA
t[n_, 0] := If[n==0, 1, Prime[n]]; t[n_, k_] := t[n, k] = t[n, k-1] + t[n-1, n-k]; a[n_] := t[n, n]; Array[a, 30, 0] (* Jean-François Alcover, Feb 12 2016 *)
PROG
(Haskell)
a000732 n = sum $ zipWith (*) (a109449_row n) a008578_list
(Python)
from itertools import accumulate, count, islice
from sympy import prime
def A000732_gen(): # generator of terms
yield 1
blist = (1, )
for i in count(1):
yield (blist := tuple(accumulate(reversed(blist), initial=prime(i))))[-1]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved