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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A380741 Decimal expansion of Sum_{k>=1} prime(k)/2^(k!).

Original entry on oeis.org

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

Views

Author

Davide Rotondo, Jan 31 2025

Keywords

Comments

Each prime can be recovered from this constant r by prime(k) = floor(r*2^(k!) - floor(r*2^((k-1)!)))*2^((k-1)*(k-1)!) when the binary positions 2^(k!) are far enough apart, which means k>=3.
Is this constant transcendental?

Examples

			1.828125417232513427734375...
		

Crossrefs

Cf. A339764.

Programs

  • PARI
    suminf(k=1, prime(k)/2^(k!)) \\ Michel Marcus, Feb 09 2025

Extensions

More terms from Amiram Eldar, Jan 31 2025