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”).

A134631
a(n) = 5*n^5 - 3*n^3 + 2*n^2. Coefficients and exponents are the prime numbers in decreasing order.
2
0, 4, 144, 1152, 4960, 15300, 38304, 83104, 162432, 293220, 497200, 801504, 1239264, 1850212, 2681280, 3787200, 5231104, 7085124, 9430992, 12360640, 15976800, 20393604, 25737184, 32146272, 39772800, 48782500, 59355504, 71686944, 85987552, 102484260, 121420800, 143058304, 167675904, 195571332, 227061520
OFFSET
0,2
FORMULA
a(n) = 5*n^5 - 3*n^3 + 2*n^2.
G.f.: 4x*(1+30x+87x^2+32x^3)/(1-x)^6. - R. J. Mathar, Nov 14 2007
EXAMPLE
a(4)=4960 because 4^5=1024, 5*1024=5120, 4^3=64, 3*64=192, 4^2=16, 2*16=32 and we can write 5120 - 192 + 32 = 4960.
MATHEMATICA
Table[5n^5-3n^3+2n^2, {n, 0, 40}] (* or *) LinearRecurrence[{6, -15, 20, -15, 6, -1}, {0, 4, 144, 1152, 4960, 15300}, 40] (* Harvey P. Dale, Jan 20 2023 *)
PROG
(Magma)[5*n^5-3*n^3+2*n^2: n in [0..50]] // Vincenzo Librandi, Dec 14 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Nov 04 2007
EXTENSIONS
More terms from Vincenzo Librandi, Dec 14 2010
STATUS
approved