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%I #14 Apr 25 2019 23:14:21
%S 0,1,2,4,5,7,8,10,11,13,18,24,25,29,34,38,39,41,44,48,53,55,56,58,71,
%T 73,78,84,85,89,94,102,103,109,120,124,131,133,138,144,145,149,162,
%U 164,169,173,178,180,181,187,192,196,197,201
%N a(0)=0, a(1)=1, a(n) = least k>a(n-1) such that k+a(n-2) is prime.
%C For n>0 and (n mod 4)<2, a(n) is odd.
%C Same definition, but k+a(n-2) is a
%C Fibonacci number: A006498 except first two terms,
%C Lucas number: A000045 except first two terms,
%C Pell number: A089928(n-1),
%C Jacobsthal number: A215095,
%C factorial: A215096,
%C square: A194274,
%C cube: A215097,
%C triangular number: A011848(n+2),
%C oblong number: A215098.
%C Example of a related sequence definition: a(0)=0, a(1)=1, a(n) = least k>a(n-1) such that k+a(n-2) is a cube.
%H Iain Fox, <a href="/A215099/b215099.txt">Table of n, a(n) for n = 0..10000</a>
%o (Python)
%o # primes = [2,...,401]
%o prpr = 0
%o prev = 1
%o for n in range(77):
%o print prpr,
%o b = c = 0
%o while c<=prev:
%o c = primes[b] - prpr
%o b+=1
%o prpr = prev
%o prev = c
%o (PARI) first(n) = my(res = vector(n, i, i-1), k); for(x=3, n, k=res[x-1]+1; while(!isprime(k+res[x-2]), k++); res[x]=k); res \\ _Iain Fox_, Apr 22 2019 (corrected by _Iain Fox_, Apr 25 2019)
%Y Cf. A062042: a(1) = 2, a(n) = least k>a(n-1) such that k+a(n-1) is a prime.
%Y Cf. A073627, A073628.
%K nonn
%O 0,3
%A _Alex Ratushnyak_, Aug 03 2012
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