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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A085400 a(n) = abs(A085061(n-1) - A085061(n)). 2
2, 3, 13, 5, 7, 17, 19, 11, 23, 29, 31, 41, 37, 43, 47, 53, 59, 61, 67, 71, 83, 73, 79, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 157, 151, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes used in constructing the terms of A085061. Except for an initial part of the sequence and occasional transpositions later on (e.g. 157,151; 691,683) the primes appear in ascending order.

LINKS

Table of n, a(n) for n=1..59.

EXAMPLE

a(8) = abs(A085061(7) - A085061(8)) = abs(23 - 34) = 11.

PROG

(PARI) {in(n, v)=local(j, s, b); j=1; s=matsize(v)[2]; b=1; while(b&&j<=s, if(n==v[j], b=0, j++)); !b}

{a=1; v=[]; for(n=1, 60, p=2; t=1; while(t>0, if(in(p, v), p=nextprime(p+1), if(!isprime(2*a+p), t=0; b=a+p, if(p<a&&!isprime(2*a-p), t=0; b=a-p, p=nextprime(p+1))))); v=concat(v, p); print1(p, ", "); a=b)}

CROSSREFS

Cf. A085061, A085402.

Sequence in context: A067182 A191000 A085402 * A067523 A035515 A076988

Adjacent sequences:  A085397 A085398 A085399 * A085401 A085402 A085403

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Jun 28 2003

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 February 22 18:29 EST 2018. Contains 299469 sequences. (Running on oeis4.)