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A139619
a(n) = 171*n + 19.
3
19, 190, 361, 532, 703, 874, 1045, 1216, 1387, 1558, 1729, 1900, 2071, 2242, 2413, 2584, 2755, 2926, 3097, 3268, 3439, 3610, 3781, 3952, 4123, 4294, 4465, 4636, 4807, 4978, 5149, 5320, 5491, 5662, 5833, 6004, 6175, 6346, 6517, 6688
OFFSET
0,1
COMMENTS
Numbers of the 19th column of positive numbers in the square array of nonnegative and polygonal numbers A139600. Also, numbers of the 19th column in the square array A057145.
FORMULA
From Chai Wah Wu, Apr 14 2017: (Start)
a(n) = 2*a(n-1) - a(n-2) for n > 1.
G.f.: (152*x + 19)/(x - 1)^2. (End)
From Elmo R. Oliveira, Apr 11 2024: (Start)
E.g.f.: 19*exp(x)*(1 + 9*x).
a(n) = 19*A017173(n) = 19*(A051682(n+1) - A051682(n)). (End)
MATHEMATICA
Range[0, 100]*171 + 19 (* Paolo Xausa, Apr 17 2024 *)
PROG
(Magma) [19*(9*n + 1): n in [0..50]]; // Vincenzo Librandi, Jul 23 2011
(PARI) a(n)=171*n+19 \\ Charles R Greathouse IV, Oct 05 2011
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, May 21 2008
STATUS
approved