A085076 Triangular numbers > 0 with a prime signature that has not occurred earlier.

1, 3, 6, 28, 36, 66, 120, 136, 210, 276, 300, 496, 528, 630, 1176, 2016, 2080, 3240, 3570, 4560, 4950, 5460, 6216, 8128, 8256, 9180, 25200, 29403, 32640, 32896, 37128, 39060, 41328, 41616, 51040, 61776, 64980, 73920, 79800, 93096, 97020, 103740, 115440

Offset

1,2

Links

Donovan Johnson, Table of n, a(n) for n = 1..1000

Prog

(PARI) e=vector(22); for(j=1, 22, e[j]=concat(Str(j), ", ")); ps=vector(1000); c=0; for(m=1, 7388415, t=m*(m+1)\2; om=omega(t); f=factorint(t); v=vector(om); for(j=1, om, v[j]=f[j, 2]); v=vecsort(v, , 4); st=""; for(j=1, om, st=concat(st, e[v[j]])); fd=0; for(j=1, c, if(st==ps[j], fd=1; j=c)); if(fd==0, c++; write("b085076.txt", c " " t); ps[c]=st)) /* Donovan Johnson, May 26 2013 */

Crossrefs

Sequence in context: A246753 A247016 A083675 * A076711 A075088 A102428

Adjacent sequences: A085073 A085074 A085075 * A085077 A085078 A085079

Keyword

nonn

Author

Amarnath Murthy, Jul 01 2003

Extensions

More terms from David Wasserman, Jan 14 2005

Offset corrected by Donovan Johnson, May 26 2013

Status

approved