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%I #15 Mar 08 2020 11:40:34
%S 1,3,4,7,8,11,12,15,20,21,26,29,30,33,38,43,44,49,52,53,58,61,66,73,
%T 76,77,80,81,84,97,100,105,106,115,116,121,126,129,134,139,140,149,
%U 150,153,154,165,176,179,180,183
%N Slowest increasing sequence where a(n)+n is prime.
%C Appears to be closely related to A014692.
%e (1)+1=2, which is prime; (3)+2=5=prime; (4)+3=7=prime; (7)+4=11=prime; (8)+5=13=prime; etc.
%p A107819 := proc(n)
%p option remember;
%p if n = 1 then
%p return 1;
%p else
%p for a from procname(n-1)+1 do
%p if isprime(a+n) then
%p return a;
%p end if;
%p end do:
%p end if;
%p end proc: # _R. J. Mathar_, Sep 05 2011
%o (Sage)
%o @cached_function
%o def A107819(n):
%o prev = (-1 if n == 1 else A107819(n-1))
%o return next_prime(prev+n)-n # _D. S. McNeil_, Sep 05 2011
%K easy,nonn
%O 1,2
%A _Eric Angelini_, Jun 11 2005
%E Corrected by _R. J. Mathar_, Sep 05 2011
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