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A307950
Primes that are the sum of two prime-indexed triangular numbers.
1
31, 43, 97, 157, 181, 193, 281, 367, 463, 499, 587, 709, 769, 1051, 1381, 1459, 1621, 1831, 1861, 2081, 2281, 2293, 2377, 2473, 2647, 2707, 2713, 2729, 2767, 2837, 3019, 3163, 3251, 3259, 3313, 3709, 3863, 4021, 4447, 4591, 4759, 4943, 4951, 5051, 5179, 5647, 5791, 5861, 5869, 5881, 6217, 6271
OFFSET
1,1
COMMENTS
Primes of the form A034953(i) + A034953(j).
There are primes with more than one expression of this form; e.g., 18749 = A034953(4) + A034953(44) = A034953(19) + A034953(42).
LINKS
EXAMPLE
a(3) = 97 is a term because 97 = 6 + 91 is prime where 6=A000217(3) and 91=A000217(13) are in A034953.
MAPLE
A034953:= map(t ->t*(t+1)/2, [seq(ithprime(i), i=1..100)]):
A:= select(t -> t <= A034953[-1]+3 and isprime(t), {seq(seq(A034953[i]+A034953[j], j=i+1..100), i=1..99)}):
sort(convert(A, list));
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, May 07 2019
STATUS
approved