login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A056928 Average of smallest prime greater than n^2 and largest prime less than n^2. 4
4, 9, 15, 26, 34, 50, 64, 81, 99, 120, 144, 170, 195, 225, 254, 288, 324, 363, 399, 441, 483, 532, 574, 625, 675, 730, 780, 846, 897, 960, 1026, 1089, 1158, 1226, 1294, 1370, 1443, 1517, 1599, 1681, 1768, 1854, 1941, 2022, 2121, 2210, 2303, 2405, 2490 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Hugo Pfoertner, Table of n, a(n) for n = 2..10000

FORMULA

a(n) = (A007491(n) - A053001(n))/2.

a(n) = A000290(n) + (A053000(n)-A056927(n))/2.

a(n) = A000290(n) - A056929(n).

EXAMPLE

a(4)=15 because smallest prime greater than 4^2 is 17, largest prime less than 4^2 is 13 and average of 17 and 13 is 15

MATHEMATICA

Table[n2=n^2; (NextPrime[n2, -1]+NextPrime[n2])/2, {n, 2, 100}] (* Vladimir Joseph Stephan Orlovsky, Mar 09 2011*)

PROG

(PARI) a(n) = (nextprime(n^2) + precprime(n^2))/2; \\ Michel Marcus, May 20 2018

CROSSREFS

Cf. A007491, A053000, A053001, A056927, A056929, A056930, A056931.

Sequence in context: A030664 A070160 A244672 * A225283 A122964 A301254

Adjacent sequences:  A056925 A056926 A056927 * A056929 A056930 A056931

KEYWORD

easy,nonn

AUTHOR

Henry Bottomley, Jul 12 2000

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 30 05:08 EDT 2020. Contains 334712 sequences. (Running on oeis4.)