login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A378569
Irregular triangle read by rows where row n lists the divisors of prime(4*n+8) + 2*n + 3.
1
1, 2, 3, 6, 7, 14, 21, 42, 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 1, 2, 4, 5, 10, 20, 25, 50, 100, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120, 1, 2, 73, 146, 1, 2, 3, 4, 6, 7, 8, 12, 14, 21, 24, 28, 42, 56, 84, 168, 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 192, 1, 2, 107, 214
OFFSET
1,2
EXAMPLE
Triangle begins:
k=1 2 3 4 5 6 7 8
n=1: 1, 2, 3, 6, 7, 14, 21, 42 (A018258)
n=2: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60 (A018266)
...
MATHEMATICA
Flatten[Table[Flatten[Divisors[2*n+3+Prime[4*n+8]]], {n, 1, 30}]]
PROG
(Magma) [Divisors(NthPrime(4*n+8)+(2*n+3)): n in [1..40]];
KEYWORD
nonn,less,tabf,new
AUTHOR
Vincenzo Librandi, Dec 01 2024
STATUS
approved