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A083517
Triangular numbers which are one more than a product of distinct triangular numbers.
1
91, 136, 946, 1081, 1711, 1891, 2701, 5671, 7021, 8911, 10585, 11935, 13861, 14365, 18145, 19306, 21736, 25651, 26335, 29161, 32131, 36856, 41041, 44551, 49141, 55945, 64261, 65341, 69751, 70876, 82621, 92665, 93961, 106030, 107416, 108811
OFFSET
1,1
LINKS
EXAMPLE
91 = 6*15 + 1, 1081 = 3*10*36 + 1.
PROG
(PARI) upto(lim)={my(v=[1]); for(k=2, oo, my(t=k*(k+1)/2); if(t\3>lim, break); my(s=(lim-1)\t); v=setunion(v, t*select(j->j<=s, v))); [j+1 | j<-v, ispolygonal(j+1, 3)]} \\ Andrew Howroyd, Sep 21 2024
CROSSREFS
Cf. A000217.
Sequence in context: A353062 A260974 A020301 * A088983 A045934 A051347
KEYWORD
nonn
AUTHOR
Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 05 2003
EXTENSIONS
Corrected and extended by David Wasserman, Nov 19 2004
Offset changed by Andrew Howroyd, Sep 21 2024
STATUS
approved