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

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A106587 Sum of n-th prime squared and n-th perfect square. 4
5, 13, 34, 65, 146, 205, 338, 425, 610, 941, 1082, 1513, 1850, 2045, 2434, 3065, 3770, 4045, 4850, 5441, 5770, 6725, 7418, 8497, 10034, 10877, 11338, 12233, 12722, 13669, 17090, 18185, 19858, 20477, 23426, 24097, 26018, 28013, 29410, 31529, 33722 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) is itself prime for a(1) = 5, a(2) = 13, a(10) = 941, a(20) = 5441, a(30) = 13669, a(34) = 20477, a(36) = 24097, ... a(n) is a semiprime for a(3) = 34 = 2 * 17, a(4) = 65 = 5 * 13, a(5) = 146 = 2 * 73, a(6) = 205 = 5 * 41, a(11) = 1082 = 2 * 541, a(12) = 1513 = 17 * 89, a(14) = 2045 = 5 * 409, a(15) = 2434 = 2 * 1217, a(16) = 3065 = 5 * 613, a(18) = 4045 = 5 * 809, a(23) = 7418 = 2 * 3709, a(24) = 8497 = 29 * 293, a(26) = 10877 = 73 * 149, a(27) = 11338 = 2 * 5669, a(28) = 12233 = 13 * 941, a(29) = 12722 = 2 * 6361, a(32) = 18185 = 5 * 3637, a(33) = 19858 = 2 * 9929, a(37) = 26018 = 2 * 13009, a(38) = 28013 = 109 * 257, a(40) = 31529 = 41 * 769, ... - Jonathan Vos Post, May 14 2005

LINKS

Table of n, a(n) for n=1..41.

EXAMPLE

a(5)=146 because 121 (fifth prime^2) + 25 (fifth square) = 146.

MATHEMATICA

Table[Prime[n]^2 + n^2, {n, 50}]

CROSSREFS

Cf. A014688, A076368, A075526, A001248, A000290.

Sequence in context: A146917 A283329 A201170 * A034509 A034521 A092647

Adjacent sequences:  A106584 A106585 A106586 * A106588 A106589 A106590

KEYWORD

easy,nonn

AUTHOR

Alexandre Wajnberg, May 10 2005

EXTENSIONS

Extended by Ray Chandler, May 13 2005

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 30 06:51 EDT 2017. Contains 287302 sequences.