OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10011 (first 141 antidiagonals, flattened)
EXAMPLE
Array starts
1 2 3 4 5 6 7 8 9 10
3 4 5 7 8 9 10 11 13 16
3 4 5 6 8 10 11 14 16 17
7 8 9 10 11 14 15 16 18 20
2 10 11 12 15 22 23 24 28 29
3 4 5 6 8 9 12 13 17 26
10 13 15 18 20 24 25 27 28 32
2 4 8 9 10 19 20 21 24 25
2 3 9 10 13 15 16 17 24 27
5 7 8 9 12 13 14 18 19 20
T(3,3) = 5 is a term because the sum of the 2*3 - 1 = 5 primes starting at prime(5) = 11 is 11 + 13 + 17 + 19 + 23 = 83, which is prime.
MAPLE
P:= select(isprime, [2, seq(i, i=3..10^6, 2)]):
SP:= ListTools:-PartialSums(P):
A:= Matrix(20, 20): A[1, 1]:= 1:
for m from 1 to 20 do
if m = 1 then count:= 1 else count:= 0 fi;
for k from 1 while count < 20 do
if isprime(SP[k+2*m-1]-SP[k]) then
count:= count+1; A[m, count]:= k+1 fi
od od:
[seq(seq(A[i, m-i], i=1..m-1), m=2..21)];
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Zak Seidov and Robert Israel, May 07 2024
STATUS
approved