login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A062021 Let P(n) = { 2,3,5,7,...,p(n) } where p(n) is n-th prime; then a(1) =0 and a(n) = Sum [mod{p(i)^2 - p(j)^2}], for all i and j from 1 to n. 0
0, 5, 42, 151, 548, 1185, 2542, 4403, 7608, 13621, 20834, 32535, 47980, 65609, 88278, 119947, 162368, 208869, 269194, 340007, 416580, 512305, 622286, 756003, 925432, 1114661, 1314498, 1537015, 1771628, 2031993, 2393158, 2786315 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..32.

FORMULA

a(n) = 2*a(n-1) + (n-1)*(p(n)^2-p(n-1)^2) - a(n-2)

EXAMPLE

a(3) = (5^2-2^2) + (5^2-3^2) + (3^2-2^2) = 42, P(3) = {2,3,5}.

CROSSREFS

Sequence in context: A025173 A222474 A266021 * A241780 A215785 A082145

Adjacent sequences:  A062018 A062019 A062020 * A062022 A062023 A062024

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Jun 02 2001

EXTENSIONS

More terms and formula from Larry Reeves (larryr(AT)acm.org), Jun 06 2001

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 February 16 03:26 EST 2019. Contains 320140 sequences. (Running on oeis4.)