login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A071217 Numbers k such that the largest prime factor of the sum of successive primes p(k) + p(k+1) is greater than k. 1
1, 9, 11, 12, 19, 23, 24, 29, 31, 32, 51, 54, 58, 63, 67, 71, 75, 76, 77, 84, 86, 87, 93, 95, 97, 103, 108, 110, 124, 128, 136, 151, 158, 159, 164, 169, 188, 191, 192, 200, 202, 205, 208, 210, 211, 216, 227, 232, 241, 243, 245, 246, 247, 252, 265, 273, 278, 282 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..58.

FORMULA

A071216(k) > k.

EXAMPLE

p(9) + p(10) = 23 + 29 = 52 = 2*2*13 and 13 > 10, so index 9 is here; it is the 2nd term.

MATHEMATICA

pf[x_] := Part[Reverse[Flatten[FactorInteger[x]]], 2] Do[s=pf[Prime[n+1]+Prime[n]]; If[Greater[s, n], Print[n]], {n, 1, 1000}]

CROSSREFS

Cf. A001043, A006530, A071216.

Sequence in context: A031078 A216292 A250295 * A064930 A158607 A070699

Adjacent sequences:  A071214 A071215 A071216 * A071218 A071219 A071220

KEYWORD

nonn

AUTHOR

Labos Elemer, May 17 2002

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 January 28 18:56 EST 2022. Contains 350657 sequences. (Running on oeis4.)