A374851 Obverse convolution A000040**A000040; see Comments.

4, 25, 294, 5184, 169000, 6350400, 331218944, 18517766400, 1288408000000, 124147372916736, 12047030383804416, 1481741383824000000, 199987846858565222400, 26836516406718627840000, 3937581724026934119628800, 668393794316928024576000000, 130212266115912538521600000000, 25085181032622344612780605440000

Offset

1,1

Comments

See A374848 for the definition of obverse convolution and a guide to related sequences. a(2k+1) is a square for k>=0. Conjecture: every positive integer divides a(n) for infinitely many n.

Links

Table of n, a(n) for n=1..18.

Mathematica

s[n_] := Prime[n]; t[n_] := Prime[n];
u[n_] := Product[s[k] + t[n + 1 - k], {k, 1, n}]
Table[u[n], {n, 1, 18}]

Crossrefs

Cf. A000040, A374848.

Sequence in context: A058791 A216660 A352859 * A350585 A238510 A222982

Adjacent sequences: A374848 A374849 A374850 * A374852 A374853 A374854

Keyword

nonn

Author

Clark Kimberling, Aug 05 2024

Status

approved