A244806
The 180-degree spoke (or ray) of a hexagonal spiral of Ulam.
Original entry on oeis.org
1, 18, 59, 124, 213, 326, 463, 624, 809, 1018, 1251, 1508, 1789, 2094, 2423, 2776, 3153, 3554, 3979, 4428, 4901, 5398, 5919, 6464, 7033, 7626, 8243, 8884, 9549, 10238, 10951, 11688, 12449, 13234, 14043, 14876, 15733, 16614, 17519, 18448, 19401, 20378, 21379, 22404, 23453, 24526, 25623
Offset: 1
See A056105 example section for its diagram.
Cf.
A056105,
A244802,
A056106,
A244803,
A056107,
A244804,
A056108,
A244805,
A056109,
A003215,
A033577.
A244802
The 60-degree spoke (or ray) of a hexagonal spiral of Ulam.
Original entry on oeis.org
1, 10, 43, 100, 181, 286, 415, 568, 745, 946, 1171, 1420, 1693, 1990, 2311, 2656, 3025, 3418, 3835, 4276, 4741, 5230, 5743, 6280, 6841, 7426, 8035, 8668, 9325, 10006, 10711, 11440, 12193, 12970, 13771, 14596, 15445, 16318, 17215, 18136, 19081, 20050, 21043, 22060, 23101, 24166, 25255
Offset: 1
See A056105 example section for a diagram.
A244803
The 360 degree spoke (or ray) of a hexagonal spiral of Ulam.
Original entry on oeis.org
1, 12, 47, 106, 189, 296, 427, 582, 761, 964, 1191, 1442, 1717, 2016, 2339, 2686, 3057, 3452, 3871, 4314, 4781, 5272, 5787, 6326, 6889, 7476, 8087, 8722, 9381, 10064, 10771, 11502, 12257, 13036, 13839, 14666, 15517, 16392, 17291, 18214, 19161, 20132, 21127, 22146, 23189, 24256, 25347
Offset: 1
See A056105 example section for a diagram.
Cf.
A056105,
A244802,
A056106,
A056107,
A244804,
A056108,
A244805,
A056109,
A244806,
A003215,
A033577.
A244804
The 300-degree spoke (or ray) of a hexagonal spiral of Ulam.
Original entry on oeis.org
1, 14, 51, 112, 197, 306, 439, 596, 777, 982, 1211, 1464, 1741, 2042, 2367, 2716, 3089, 3486, 3907, 4352, 4821, 5314, 5831, 6372, 6937, 7526, 8139, 8776, 9437, 10122, 10831, 11564, 12321, 13102, 13907, 14736, 15589, 16466, 17367, 18292, 19241, 20214, 21211, 22232, 23277, 24346, 25439
Offset: 1
See A056105 example section for its diagram.
Cf.
A056105,
A244802,
A056106,
A244803,
A056107,
A056108,
A244805,
A056109,
A244806,
A003215,
A033577.
Original entry on oeis.org
1, 2, 6, 9, 17, 22, 34, 41, 57, 66, 86, 97, 121, 134, 162, 177, 209, 226, 262, 281, 321, 342, 386, 409, 457, 482, 534, 561, 617, 646, 706, 737, 801, 834, 902, 937, 1009, 1046, 1122, 1161, 1241, 1282, 1366, 1409, 1497, 1542, 1634, 1681, 1777, 1826, 1926, 1977
Offset: 0
Cf.
A056109: numbers of the form m*(3*m+2)+1 for nonnegative m.
-
a257083 n = a257083_list !! n
a257083_list = scanl1 (+) a257088_list
-
[(6*n*(n+1) + (2*n+1)*(-1)^n + 7)/8 : n in [0..60]]; // Wesley Ivan Hurt, Oct 30 2022
-
Table[(6 n (n + 1) + (2 n + 1) (-1)^n + 7)/8, {n, 0, 60}] (* Bruno Berselli, Jan 05 2016 *)
-
vector(60, n, n--; (6*n*(n+1)+(2*n+1)*(-1)^n+7)/8) \\ Bruno Berselli, Jan 05 2016
A270710
a(n) = 3*n^2 + 2*n - 1.
Original entry on oeis.org
-1, 4, 15, 32, 55, 84, 119, 160, 207, 260, 319, 384, 455, 532, 615, 704, 799, 900, 1007, 1120, 1239, 1364, 1495, 1632, 1775, 1924, 2079, 2240, 2407, 2580, 2759, 2944, 3135, 3332, 3535, 3744, 3959, 4180, 4407, 4640, 4879, 5124, 5375, 5632, 5895, 6164, 6439, 6720, 7007, 7300, 7599
Offset: 0
a(0) = 3*0^2 + 2*0 - 1 = -1;
a(1) = 3*1^2 + 2*1 - 1 = 4;
a(2) = 3*2^2 + 2*2 - 1 = 15;
a(3) = 3*3^2 + 2*3 - 1 = 32, etc.
-
List([0..50], n -> 3*n^2+2*n-1); # Bruno Berselli, Feb 16 2018
-
[3*n^2+2*n-1: n in [0..50]]; // Bruno Berselli, Mar 25 2016
-
Table[3 n^2 + 2 n - 1, {n, 0, 50}]
LinearRecurrence[{3, -3, 1}, {-1, 4, 15}, 51]
-
makelist(3*n^2+2*n-1, n, 0, 50); /* Bruno Berselli, Mar 25 2016 */
-
Vec((-1 + 7*x)/(1 - x)^3 + O(x^60)) \\ Michel Marcus, Mar 22 2016
-
lista(nn) = {for(n=0, nn, print1(3*n^2 + 2*n - 1, ", ")); } \\ Altug Alkan, Mar 25 2016
-
vector(50, n, n--; 3*n^2+2*n-1) \\ Bruno Berselli, Mar 25 2016
-
[3*n^2+2*n-1 for n in (0..50)] # Bruno Berselli, Mar 25 2016
A059045
Square array T(n,k) read by antidiagonals where T(0,k) = 0 and T(n,k) = 1 + 2k + 3k^2 + ... + n*k^(n-1).
Original entry on oeis.org
0, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 6, 5, 1, 0, 1, 10, 17, 7, 1, 0, 1, 15, 49, 34, 9, 1, 0, 1, 21, 129, 142, 57, 11, 1, 0, 1, 28, 321, 547, 313, 86, 13, 1, 0, 1, 36, 769, 2005, 1593, 586, 121, 15, 1, 0, 1, 45, 1793, 7108, 7737, 3711, 985, 162, 17, 1, 0, 1, 55, 4097, 24604, 36409
Offset: 0
0, 0, 0, 0, 0, 0, 0, 0, 0, ...
1, 1, 1, 1, 1, 1, 1, 1, 1, ...
1, 3, 5, 7, 9, 11, 13, 15, 17, ...
1, 6, 17, 34, 57, 86, 121, 162, 209, ...
1, 10, 49, 142, 313, 586, 985, 1534, 2257, ...
1, 15, 129, 547, 1593, 3711, 7465, 13539, 22737, ...
1, 21, 321, 2005, 7737, 22461, 54121, 114381, 219345, ...
1, 28, 769, 7108, 36409, 131836, 380713, 937924, 2054353, ...
A113630
1 + 2*n + 3*n^2 + 4*n^3 + 5*n^4 + 6*n^5 + 7*n^6 + 8*n^7 + 9*n^8.
Original entry on oeis.org
1, 45, 4097, 83653, 757305, 4272461, 17736745, 59409477, 169826513, 429794605, 987654321, 2098573445, 4178995657, 7879732173, 14181546905, 24517448581, 40926266145, 66242446637, 104327377633, 160347899205, 241108033241
Offset: 0
a(3) = 1 + 2*3 + 3*3^2 + 4*3^3 + 5*3^4 + 6*3^5 + 7*3^6 + 8*3^7 + 9*3^8 = 83653 is prime.
a(5) = 1 + 2*5 + 3*5^2 + 4*5^3 + 5*5^4 + 6*5^5 + 7*5^6 + 8*5^7 + 9*5^8 = 4272461 is prime.
a(8) = 1 + 2*8 + 3*8^2 + 4*8^3 + 5*8^4 + 6*8^5 + 7*8^6 + 8*8^7 + 9*8^8 = 169826513 is prime.
a(23) = 1 + 2*23 + 3*23^2 + 4*23^3 + 5*23^4 + 6*23^5 + 7*23^6 + 8*23^7 + 9*23^8 = 733113789893 is prime.
- Chai Wah Wu, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (9,-36,84,-126,126,-84,36,-9,1).
-
a113630 n = sum $ zipWith (*) [1..9] $ iterate (* n) 1
-- Reinhard Zumkeller, Nov 22 2014
-
[1+2*n+3*n^2+4*n^3+5*n^4+6*n^5+7*n^6+8*n^7+9*n^8: n in [0..20]]; // Vincenzo Librandi, Nov 09 2014
-
CoefficientList[Series[(5 x^8 + 1548 x^7 + 31360 x^6 + 129620 x^5 + 148266 x^4 + 48316 x^3 + 3728 x^2 + 36 x + 1) / (1 - x)^9, {x, 0, 40}], x] (* Vincenzo Librandi, Nov 09 2014 *)
With[{c=Total[Table[k n^(k-1),{k,9}]]},Table[c,{n,0,30}]] (* or *) LinearRecurrence[ {9,-36,84,-126,126,-84,36,-9,1},{1,45,4097,83653,757305,4272461,17736745,59409477,169826513},30] (* Harvey P. Dale, Jul 18 2017 *)
-
vector(100,n,1 + 2*(n-1)+ 3*(n-1)^2 + 4*(n-1)^3 + 5*(n-1)^4 + 6*(n-1)^5 + 7*(n-1)^6 + 8*(n-1)^7 + 9*(n-1)^8) \\ Derek Orr, Nov 09 2014
-
A113630_list, m = [1], [362880, -1229760, 1607760, -1011480, 309816, -40752, 1584, -4, 1]
for _ in range(10**3):
for i in range(8):
m[i+1]+= m[i]
A113630_list.append(m[-1]) # Chai Wah Wu, Nov 09 2014
A067389
a(n) = 3*n^3 + 2*n^2 + n.
Original entry on oeis.org
0, 6, 34, 102, 228, 430, 726, 1134, 1672, 2358, 3210, 4246, 5484, 6942, 8638, 10590, 12816, 15334, 18162, 21318, 24820, 28686, 32934, 37582, 42648, 48150, 54106, 60534, 67452, 74878, 82830, 91326, 100384, 110022, 120258, 131110, 142596
Offset: 0
-
[3*n^3 + 2*n^2 + n: n in [0..60]]; // Vincenzo Librandi, May 08 2011
-
a:=n->n+2*n^2+3*n^3: seq(a(n), n=0..36); # Zerinvary Lajos, Oct 05 2007
-
Table[3*n^3+2*n^2+n,{n,0,80}] (* Vladimir Joseph Stephan Orlovsky, May 07 2011 *)
LinearRecurrence[{4,-6,4,-1},{0,6,34,102},40] (* Harvey P. Dale, Oct 01 2019 *)
A113653
Isolated semiprimes in the hexagonal spiral.
Original entry on oeis.org
6, 51, 69, 82, 91, 183, 194, 221, 249, 265, 287, 289, 309, 314, 319, 323, 355, 371, 403, 417, 437, 469, 478, 511, 517, 519, 533, 579, 589, 649, 681, 689, 731, 749, 758, 807, 838, 849, 926, 943, 951, 961, 965, 979, 1011, 1018, 1037, 1055, 1057, 1067, 1077, 1099, 1126, 1145, 1149, 1154, 1159
Offset: 1
The spiral begins:
120-119-118-117-116-115-114
/ \
121 85--84--83-*82*-81--80 113
/ / \ \
122 86 56--55--54--53--52 79 112
/ / / \ \ \
123 87 57 33--32--31--30 *51* 78 111
/ / / / \ \ \ \
124 88 58 34 16--15--14 29 50 77 110
/ / / / / \ \ \ \ \
125 89 59 35 17 5---4 13 28 49 76 109
/ / / / / / \ \ \ \ \ \
126 90 60 36 18 *6* 0 3 12 27 48 75 108
/ / / / / / / / / / / / /
127 *91* 61 37 19 7 1---2 11 26 47 74 107 146
\ \ \ \ \ \ / / / / / /
128 92 62 38 20 8---9--10 25 46 73 106 145
\ \ \ \ \ / / / / /
129 93 63 39 21--22--23--24 45 72 105 144
\ \ \ \ / / / /
130 94 64 40--41--42--43--44 71 104 143
\ \ \ / / /
131 95 65--66--67--68-*69*-70 103 142
\ \ / /
132 96--97--98--99-100-101-102 141
\ /
133-134-135-136-137-138-139-140
- Abbott, P. (Ed.). "Mathematica One-Liners: Spiral on an Integer Lattice." Mathematica J. 1, 39, 1990.
For the sequence of isolated primes see
A335916.
Related sequences:
A113519 Semiprimes in 1st spoke of a hexagonal spiral starting at 1 (
A056105).
Corrected and edited by
N. J. A. Sloane, Jun 27 2020. Thanks to Jeffrey K. Aronson for pointing out the error in the original submission.
Comments