A230954 Boustrophedon transform of composite numbers.

4, 10, 24, 59, 162, 526, 2016, 8978, 45696, 261760, 1666308, 11668652, 89141580, 737740174, 6575238599, 62788901290, 639562492327, 6921688171153, 79316703841369, 959397056891093, 12215422719238138, 163308172248420391, 2287234651735371577

Offset

0,1

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

Index entries for sequences related to boustrophedon transform

Formula

a(n) = sum(A109449(n,k)*A002808(k+1): k=0..n).

Mathematica

cc = Select[Range[max = 40], CompositeQ]; 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)
a230954 n = sum $ zipWith (*) (a109449_row n) a002808_list
(Python)
from itertools import accumulate, count, islice
from sympy import composite
def A230954_gen(): # generator of terms
    blist = tuple()
    for i in count(1):
        yield (blist := tuple(accumulate(reversed(blist), initial=composite(i))))[-1]
A230954_list = list(islice(A230954_gen(), 40)) # Chai Wah Wu, Jun 12 2022

Crossrefs

Cf. A230955, A000747, A000732, A230953.

Sequence in context: A080617 A080628 A225127 * A190169 A212330 A291412

Adjacent sequences: A230951 A230952 A230953 * A230955 A230956 A230957

Keyword

nonn

Author

Reinhard Zumkeller, Nov 03 2013

Status

approved