A279021 Triangle read by rows, giving the arithmetic progressions of prime-indexed primes in A278735.

3, 3, 5, 5, 11, 17, 353, 431, 509, 587, 13297, 21937, 30577, 39217, 47857, 1561423, 2716423, 3871423, 5026423, 6181423, 7336423, 291461857, 373881397, 456300937, 538720477, 621140017, 703559557, 785979097

Offset: 1

Author

Bobby Jacobs, Dec 03 2016

Keywords

• nonn
• hard
• more
• tabl

Comments

Suggested by Charles R Greathouse IV in A278735.

The first set of 4 prime-indexed primes in arithmetic progression (353, 431, 509, and 587) contains consecutive terms of A142160.

The first set of 5 prime-indexed primes in arithmetic progression contains 3 numbers that are anagrams of each other (13297, 21937, and 39217).

Examples

			a(7) = 353, a(8) = 431, a(9) = 509, and a(10) = 587 because 353 = prime(prime(20)), 431 = prime(prime(23)), 509 = prime(prime(25)), 587 = prime(prime(28)), and 431-353 = 509-431 = 587-509 = 78.
The triangle begins:
3;
3, 5;
5, 11, 17;
353, 431, 509, 587;
13297, 21937, 30577, 39217, 47857;
1561423, 2716423, 3871423, 5026423, 6181423, 7336423;
...
		

Crossrefs

Cf. A006450, A133277, A142160, A274825, A278735, A279062.

Extensions

a(22)-a(28) from Charles R Greathouse IV, Dec 27 2016