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 44-54 1996 (Abstract, pdf, ps).
Wikipedia, Boustrophedon transform
MATHEMATICA
cc = Select[Range[max = 40], !PrimeQ[#]&]; t[n_, 0] := cc[[n+1]]; t[n_, k_] := t[n, k] = t[n, k-1] + t[n-1, n-k]; a[n_] := t[n, n]; Array[a, cc // Length, 0] (* Jean-François Alcover, Feb 12 2016 *)
PROG
(Haskell)
a230955 n = sum $ zipWith (*) (a109449_row n) a018252_list
(Python)
from itertools import accumulate, count, islice
from sympy import composite
def A230955_gen(): # generator of terms
yield 1
blist = (1, )
for i in count(1):
yield (blist := tuple(accumulate(reversed(blist), initial=composite(i))))[-1]
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Nov 03 2013
STATUS
approved