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A076578
Triangular numbers which are 4-almost primes.
3
36, 136, 210, 276, 351, 666, 820, 1035, 1225, 1275, 1326, 1431, 1770, 1830, 1953, 2145, 2346, 2415, 2775, 2926, 3003, 3486, 3916, 4005, 4186, 4278, 5050, 5356, 5565, 6105, 6555, 6670, 6903, 7626, 8001, 8385, 8646, 9316, 9730, 10731, 11175, 11325, 11476, 11935
OFFSET
1,1
LINKS
EXAMPLE
36 is a term because it is a triangular number and 36 = 2*2*3*3, i.e., is a product of 4 prime factors so is a 4-almost prime.
MAPLE
q:= n-> is(numtheory[bigomega](n)=4):
select(q, [i*(i+1)/2$i=0..200])[]; # Alois P. Heinz, Mar 27 2024
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Shyam Sunder Gupta, Oct 19 2002
STATUS
approved