A386364 Irregular triangle read by rows. The prime numbers corresponding to the distinct prime chains in A385871. Also a permutation of the primes.
2, 3, 7, 5, 11, 23, 13, 17, 19, 37, 29, 53, 31, 41, 73, 43, 47, 83, 137, 59, 61, 67, 71, 79, 131, 89, 97, 157, 101, 163, 103, 167, 107, 173, 109, 113, 127, 139, 149, 233, 353, 151, 179, 277, 181, 281, 421, 613, 191, 193, 197, 199, 211, 223, 337, 227, 229, 239, 241, 251, 257, 263, 269, 271
Offset: 1
Examples
The irregular triangle begins: 2, 3, 7; 5, 11, 23; 13; 17; 19, 37; 29, 53; 31; 41, 73; ...
Programs
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PARI
f(n) = my(m=1, x); while((x=(prime(n) + 2*(n - 1) + m - prime(n + m)))>= 0, if (x==0, return(m+n)); m++); \\ A385871 lista(nn) = my(list = List(), vp=vector(nn)); for (n=1, nn, if (!vp[n], my(v=Vec(prime(n)), m=n); vp[n] = 1; while(m = f(m), v=concat(v, prime(m)); if (m<=nn, vp[m]=1)); listput(list, v););); Vec(list); \\ Michel Marcus, Jul 19 2025
Extensions
More terms from Michel Marcus, Jul 19 2025
Comments