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!)
A178561 Primes q from A178548. 2
31, 11, 313, 23, 163, 53, 157, 43, 41, 71, 103, 137, 61, 127, 193, 227, 113, 109, 107, 101, 277, 127, 101, 223, 113, 181, 251, 571, 233, 409, 151, 257, 211, 317, 491, 557, 733, 367, 433, 359, 313, 491, 271, 233, 509, 281, 241, 311, 271, 373, 1163, 613, 571 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See comments in A178548.

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

G. C. Greubel, List of triples (prime(n+2), p=A178548(n), q=A178561(n)) for n=0..100

EXAMPLE

From Robert G. Wilson v, Aug 23 2010: (Start)

2*13 + prime(3) = 26 + 5 = 31 = prime(11), digsum(13)=digsum(31)=4

2*2 + prime(4) = 4 + 7 = 11 = prime(5), digsum(2)=digsum(11)=2

2*151 + prime(5) = 302 + 11 = 313 = prime(65), digsum(151)=digsum(313)=7

2*5 + prime(6) = 10 + 13 = 23 = prime(9), digsum(5)=digsum(23)=5, etc.

(End)

MATHEMATICA

f[n_] := Block[{p = 2}, While[q = 2 p + Prime[n + 2]; !PrimeQ@q || Plus @@ IntegerDigits@p != Plus @@ IntegerDigits@q, p = NextPrime@p]; q]; Array[f, 53] (* Robert G. Wilson v, Aug 23 2010 *)

PROG

(PARI) a(n) = {my(p=2, q=prime(n+2)+2*p); while ((!isprime(q) || (sumdigits(p) != sumdigits(q))), p = nextprime(p+1); q = prime(n+2) + 2*p); q; }

vector(70, n, a(n)) \\ G. C. Greubel and Michel Marcus, Feb 26 2019

CROSSREFS

Cf. A000040, A001358, A178548.

Sequence in context: A029821 A040935 A145584 * A065821 A040934 A320431

Adjacent sequences:  A178558 A178559 A178560 * A178562 A178563 A178564

KEYWORD

base,nonn

AUTHOR

Ulrich Krug (leuchtfeuer37(AT)gmx.de), May 29 2010

EXTENSIONS

All comments removed by Robert G. Wilson v, Aug 23 2010

a(37) corrected by G. C. Greubel, Feb 16 2019

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 August 13 22:34 EDT 2020. Contains 336465 sequences. (Running on oeis4.)