login
A075694
a(1)=1, then "jump over next prime": a(n) = 2 nextprime(a(n-1))-a(n-1).
4
1, 3, 7, 15, 19, 27, 31, 43, 51, 55, 63, 71, 75, 83, 95, 99, 103, 111, 115, 139, 159, 167, 179, 183, 199, 223, 231, 235, 243, 259, 267, 271, 283, 303, 311, 315, 319, 343, 351, 355, 363, 371, 375, 383, 395, 399, 403, 415, 423, 439, 447, 451, 463, 471, 487, 495
OFFSET
1,2
COMMENTS
The rule "jump over next something" can be varied. In A074487 the example "jump over next square" is given.
LINKS
FORMULA
a(1)=1, a(n) = 2 nextprime(a(n-1))-a(n-1).
EXAMPLE
a(1)=1; next prime (smallest larger than a(1))=2; "jump over" it: 2+(2-1)=3; a(2)=3; next prime (smallest larger than a(2))=5; "jump over" it: 5+(5-3)=7; a(7)=31; next prime (smallest larger than a(7))=37; "jump over" it: 37+(37-31)=43.
MAPLE
A:= Vector(100):
A[1]:= 1:
for n from 2 to 100 do A[n]:= 2*nextprime(A[n-1])-A[n-1] od:
convert(A, list); # Robert Israel, Dec 01 2020
MATHEMATICA
NestList[2*NextPrime[#]-#&, 1, 60] (* Harvey P. Dale, Aug 22 2022 *)
CROSSREFS
Cf. A075695.
Sequence in context: A089432 A111294 A092899 * A186300 A323650 A350696
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Sep 26 2002
STATUS
approved