The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A358530 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A358530

a(n) = n-th prime prime(k) such that prime(k) - prime(k-1) < prime(k-1) - prime(k-2).
(history; published version)

#18 by Hugo Pfoertner at Sun Sep 22 02:29:48 EDT 2024

STATUS

reviewed

approved

#17 by Joerg Arndt at Sun Sep 22 02:25:32 EDT 2024

STATUS

proposed

reviewed

#16 by Michel Marcus at Sat Sep 21 15:00:13 EDT 2024

STATUS

editing

proposed

#15 by Michel Marcus at Sat Sep 21 15:00:05 EDT 2024

NAME

a(n) = n-th prime pprime(k) such that pprime(k) - pprime(k-1) < pprime(k-1) - pprime(k-2).

COMMENTS

This sequence, together with A358528 and A181424, partition the set of primes >= 5. The corresponding sequences of indices, A358531, A358529, and A356347, partition the set of positive integers >= 3.

EXAMPLE

n 1 2 3 4 5 6 7

k 6 8 11 13 14 18 20

pprime(n) 13 19 31 41 43 61 71

STATUS

proposed

editing

#14 by Andrew Howroyd at Sat Sep 21 14:30:51 EDT 2024

STATUS

editing

proposed

#13 by Andrew Howroyd at Sat Sep 21 14:30:40 EDT 2024

FORMULA

a(n) = A151800(A051634(n)). - Andrew Howroyd, Sep 21 2024

STATUS

proposed

editing

#12 by Georg Fischer at Sat Sep 21 13:59:55 EDT 2024

STATUS

editing

proposed

#11 by Georg Fischer at Sat Sep 21 13:58:31 EDT 2024

FORMULA

a(n) = A051634(n) + 2.

EXTENSIONS

Incorrect formula removed by Georg Fischer, Sep 21 2024

STATUS

approved

editing

Discussion

Sat Sep 21

13:59

Georg Fischer: A051634(4)=37 differs from a(4)-2=39.

#10 by N. J. A. Sloane at Tue Nov 22 22:20:50 EST 2022

STATUS

proposed

approved

#9 by Clark Kimberling at Mon Nov 21 11:47:41 EST 2022

STATUS

editing

proposed