The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A167180 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A167180

a(n) = pi(n) plus the number of nonprimes less than prime(n).
(history; published version)

#15 by Susanna Cuyler at Mon Feb 18 08:54:56 EST 2019

STATUS

reviewed

approved

#14 by Joerg Arndt at Mon Feb 18 04:29:41 EST 2019

STATUS

proposed

reviewed

#13 by Michel Marcus at Mon Feb 18 03:06:06 EST 2019

STATUS

editing

proposed

#12 by Michel Marcus at Mon Feb 18 03:06:02 EST 2019

CROSSREFS

Cf. A000720, A014689.

STATUS

proposed

editing

#11 by Jon E. Schoenfield at Mon Feb 18 02:49:46 EST 2019

STATUS

editing

proposed

#10 by Jon E. Schoenfield at Mon Feb 18 02:49:43 EST 2019

COMMENTS

The number of primes less than n plus the number of nonprimes less than the n-th prime.

MAPLE

Contribution from R. J. Mathar, May 21 2010: (Start)

A167180 := proc(n) A000720(n)+A014689(n) ; end proc: seq(A167180(n), n=1..120) ; (End)# _R. J. Mathar_, May 21 2010

EXTENSIONS

Corrected (89 replaced by with 88, 94 by with 93, 127 by with 126, 146 by with 145 , etc.) by R. J. Mathar, May 21 2010

STATUS

approved

editing

#9 by Joerg Arndt at Sun Jun 05 02:21:16 EDT 2016

STATUS

proposed

approved

#8 by G. C. Greubel at Sat Jun 04 16:30:51 EDT 2016

STATUS

editing

proposed

#7 by G. C. Greubel at Sat Jun 04 16:30:40 EDT 2016

LINKS

G. C. Greubel, <a href="/A167180/b167180.txt">Table of n, a(n) for n = 1..1000</a>

FORMULA

a(n) = A000720(n) + A014689(n).

MATHEMATICA

Table[PrimePi[n] + Prime[n] - n , {n, 1, 20}] (* G. C. Greubel, Jun 04 2016 *)

STATUS

approved

editing

#6 by Russ Cox at Fri Mar 30 18:52:35 EDT 2012

AUTHOR

_Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), _, Oct 29 2009

Discussion

Fri Mar 30

18:52

OEIS Server: https://oeis.org/edit/global/257