The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A113496 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A113496

a(n) = smallest composite integer > c(n) and coprime to c(n), where c(n) is the n-th composite integer.
(history; published version)

#17 by Susanna Cuyler at Sun Mar 28 15:54:16 EDT 2021

STATUS

proposed

approved

#16 by Chai Wah Wu at Sun Mar 28 13:16:54 EDT 2021

STATUS

editing

proposed

#15 by Chai Wah Wu at Sun Mar 28 13:13:32 EDT 2021

PROG

return k # Chai Wah Wu, Mar 28 2021

#14 by Chai Wah Wu at Sun Mar 28 13:13:21 EDT 2021

PROG

(Python)

from sympy import isprime, gcd, composite

def A113496(n):

m = composite(n)

k = m+1

while gcd(k, m) != 1 or isprime(k):

k += 1

return k # Chai Wah Wu, Mar 28 2021

STATUS

approved

editing

#13 by Bruno Berselli at Thu Mar 04 09:20:29 EST 2021

STATUS

reviewed

approved

#12 by Joerg Arndt at Thu Mar 04 08:47:53 EST 2021

STATUS

proposed

reviewed

#11 by Michel Marcus at Thu Mar 04 06:19:45 EST 2021

STATUS

editing

proposed

#10 by Michel Marcus at Thu Mar 04 06:19:40 EST 2021

MATHEMATICA

Composite[n_Integer] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; f[n_] := Block[{k = n + 1}, While[PrimeQ@k || GCD[k, n] > 1, k++ ]; k]; Array[ f[ Composite[ # ]] &, 70] (* Robert G. Wilson v , Jan 12 2006 *)

STATUS

approved

editing

#9 by Charles R Greathouse IV at Wed Apr 09 10:12:21 EDT 2014

AUTHOR

Leroy Quet , Jan 11 2006

Discussion

Wed Apr 09

10:12

OEIS Server: https://oeis.org/edit/global/2145

#8 by N. J. A. Sloane at Wed Feb 05 20:18:15 EST 2014

AUTHOR

_Leroy Quet _ Jan 11 2006

Discussion

Wed Feb 05

20:18

OEIS Server: https://oeis.org/edit/global/2118