OFFSET
1,1
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
(1+2)+(2+3)+(4+5)=17, (4+5)+(6+7)+(10+11)=43, (6+7)+(10+11)+(12+13)=59, ...
MAPLE
N:= 10^4: # for terms <= N
pmax:= nextprime(nextprime(ceil((N+3)/6))):
T:= map(p -> 2*p-1, select(isprime, [2, seq(i, i=3..pmax, 2)])):
S:= ListTools:-PartialSums([0, op(T)]):
R:= {}:
for m from 3 by 2 while S[m] <= N do
for j from 1 do
v:= S[m+j]-S[j];
if v > N then break fi;
if isprime(v) then R:= R union {v} fi
od od:
sort(convert(R, list)); # Robert Israel, Apr 17 2026
MATHEMATICA
lst={}; Do[s=2*Prime[m]-1; Do[p=Prime[n]; s+=(2*p-1); If[PrimeQ[s], If[s<=6793, AppendTo[lst, s]]], {n, m+1, 3*5!}], {m, 1, 3*5!}]; lst=Take[Union@lst, 200]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Sep 13 2009
EXTENSIONS
Revised by Sean A. Irvine, Feb 02 2026
STATUS
approved
