OFFSET
1,1
COMMENTS
The rectangle R(i,j) has this corner:
1, 2, 4, 7, 11, 16, 22, 29, ...
3, 5, 8, 12, 17, 23, 30, 38, ...
6, 9, 13, 18, 24, 31, 39, 48, ...
10, 14, 19, 25, 32, 40, 49, 59, ...
15, 20, 26, 33, 41, 50, 60, 71, ...
21, 27, 34, 42, 51, 61, 72, 84, ...
28, 35, 43, 52, 62, 73, 85, 98, ...
FORMULA
a(n) = A004736(prime(n)). - Michel Marcus, Feb 24 2023
EXAMPLE
The 8th prime, 19, is in column 3, so a(8) = 3.
PROG
(PARI) f(n) = 1 + binomial(1 + floor(1/2 + sqrt(2*n)), 2) - n; \\ A004736
a(n) = f(prime(n)); \\ Michel Marcus, Feb 24 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jul 30 2000
EXTENSIONS
Edited by Clark Kimberling, Feb 12 2013
STATUS
approved