OFFSET
1,1
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).
EXAMPLE
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
KEYWORD
AUTHOR
Bobby Jacobs, Dec 03 2016
EXTENSIONS
a(22)-a(28) from Charles R Greathouse IV, Dec 27 2016
STATUS
approved