A341930 Decimal expansion of (A249270 + A340469)/2.

2, 0, 6, 7, 4, 3, 5, 8, 9, 1, 4, 2, 0, 2, 3, 4, 2, 2, 9, 5, 1, 8, 8, 4, 7, 0, 7, 5, 6, 6, 7, 8, 9, 5, 2, 1, 1, 1, 3, 0, 9, 3, 9, 0, 7, 9, 7, 6, 6, 8, 4, 9, 5, 5, 5, 6, 7, 6, 5, 4, 8, 5, 7, 6, 2, 0, 0, 7, 7, 3, 8, 8, 1, 5, 5, 3, 7, 6, 4, 6, 9, 2, 3, 9, 7, 1, 1, 8, 5, 8, 6, 3, 2, 5, 5, 7, 0, 0, 0, 3, 9, 6, 8

Offset

1,1

Comments

With this constant r(1) and using the formula r(n+1) = round(r(n))*(r(n) - round(r(n)) + 1.5) it is possible to obtain the sequence of prime numbers because round(r(n)) = prime(n).

Links

Table of n, a(n) for n=1..103.

Formula

r(1) = Sum_{k>=1} (prime(k)-1.5)/Product_{i=1..k-1} prime(i).

Example

2.06743589142023422951884707566789...

Prog

(PARI) suminf(k=1, (prime(k)-1.5)/prod(i=1, k-1, prime(i))) \\ Michel Marcus, Feb 23 2021

Crossrefs

Cf. A249270, A340469.

Sequence in context: A268656 A318619 A340484 * A220608 A057720 A248507

Adjacent sequences: A341927 A341928 A341929 * A341931 A341932 A341933

Keyword

nonn,cons

Author

Davide Rotondo, Feb 23 2021

Status

approved