A317313
Multiples of 13 and odd numbers interleaved.
Original entry on oeis.org
0, 1, 13, 3, 26, 5, 39, 7, 52, 9, 65, 11, 78, 13, 91, 15, 104, 17, 117, 19, 130, 21, 143, 23, 156, 25, 169, 27, 182, 29, 195, 31, 208, 33, 221, 35, 234, 37, 247, 39, 260, 41, 273, 43, 286, 45, 299, 47, 312, 49, 325, 51, 338, 53, 351, 55, 364, 57, 377, 59, 390, 61, 403, 63, 416, 65, 429, 67, 442, 69
Offset: 0
Sequences whose partial sums give the generalized k-gonal numbers:
A026741 (k=5),
A001477 (k=6), zero together with
A080512 (k=7),
A022998 (k=8),
A195140 (k=9), zero together with
A165998 (k=10),
A195159 (k=11),
A195161 (k=12),
A195312 (k=13),
A195817 (k=14),
A317311 (k=15),
A317312 (k=16).
-
Table[{13n, 2n + 1}, {n, 0, 35}] // Flatten (* or *)
CoefficientList[Series[(x^3 + 13 x^2 + x)/(x^2 - 1)^2, {x, 0, 69}], x] (* or *)
LinearRecurrence[{0, 2, 0, -1}, {0, 1, 13, 3}, 70] (* Robert G. Wilson v, Jul 26 2018 *)
-
a(n) = if(n%2==0, return((n/2)*13), return(n)) \\ Felix Fröhlich, Jul 26 2018
-
concat(0, Vec(x*(1 + 13*x + x^2) / ((1 - x)^2*(1 + x)^2) + O(x^60))) \\ Colin Barker, Jul 29 2018
A133371
Triangle read by rows: T(i,j) is the number of i-permutations of 14 objects a,b,c,d,e,f,g,h,i,j,k,l,m,n, with repetition allowed, containing j a's.
Original entry on oeis.org
1, 13, 1, 169, 26, 1, 2197, 507, 39, 1, 28561, 8788, 1014, 52, 1, 371293, 142805, 21970, 1690, 65, 1, 4826809, 2227758, 428415, 43940, 2535, 78, 1, 62748517, 33787663, 7797153, 999635, 76895, 3549, 91, 1
Offset: 0
1
13, 1
169, 26, 1
2197, 507, 39, 1
28561, 8788, 1014, 52, 1
371293, 142805, 21970, 1690, 65, 1
4826809, 2227758, 428415, 43940, 2535, 78, 1
62748517, 33787663, 7797153, 999635, 76895, 3549, 91, 1
-
for i from 0 to 7 do seq(binomial(i, j)*13^(i-j), j = 0 .. i) od;
-
Flatten[Table[Binomial[i,j] 13^(i-j),{i,0,7},{j,0,i}]] (* Harvey P. Dale, Nov 01 2011 *)
A319073
Square array read by antidiagonals upwards: T(n,k) = k*sigma(n), n >= 1, k >= 1.
Original entry on oeis.org
1, 3, 2, 4, 6, 3, 7, 8, 9, 4, 6, 14, 12, 12, 5, 12, 12, 21, 16, 15, 6, 8, 24, 18, 28, 20, 18, 7, 15, 16, 36, 24, 35, 24, 21, 8, 13, 30, 24, 48, 30, 42, 28, 24, 9, 18, 26, 45, 32, 60, 36, 49, 32, 27, 10, 12, 36, 39, 60, 40, 72, 42, 56, 36, 30, 11, 28, 24, 54, 52, 75, 48, 84, 48, 63, 40, 33, 12
Offset: 1
The corner of the square array begins:
A000203 A074400 A272027 A239050 A274535 A274536 A319527 A319528
A000027: 1, 2, 3, 4, 5, 6, 7, 8, ...
A008585: 3, 6, 9, 12, 15, 18, 21, 24, ...
A008586: 4, 8, 12, 16, 20, 24, 28, 32, ...
A008589: 7, 14, 21, 28, 35, 42, 49, 56, ...
A008588: 6, 12, 18, 24, 30, 36, 42, 48, ...
A008594: 12, 24, 36, 48, 60, 72, 84, 96, ...
A008590: 8, 16, 24, 32, 40, 48, 56, 64, ...
A008597: 15, 30, 45, 60, 75, 90, 105, 120, ...
A008595: 13, 26, 39, 52, 65, 78, 91, 104, ...
A008600: 18, 36, 54, 72, 90, 108, 126, 144, ...
...
Row n lists the multiples of
A000203(n).
Initial zeros should be omitted in the following sequences related to the rows of the array:
(Note that in the OEIS there are many other sequences that are also rows of this square array.)
-
T:=Flat(List([1..12],n->List([1..n],k->k*Sigma(n-k+1))));; Print(T); # Muniru A Asiru, Jan 01 2019
-
with(numtheory): T:=(n,k)->k*sigma(n-k+1): seq(seq(T(n,k),k=1..n),n=1..12); # Muniru A Asiru, Jan 01 2019
-
Table[k DivisorSigma[1, #] &[m - k + 1], {m, 12}, {k, m}] // Flatten (* Michael De Vlieger, Dec 31 2018 *)
A062903
Numbers n such that n and its reversal are both multiples of 13.
Original entry on oeis.org
0, 494, 585, 676, 767, 858, 949, 1001, 1495, 1586, 1677, 1768, 1859, 2002, 2496, 2587, 2678, 2769, 3003, 3497, 3588, 3679, 4004, 4498, 4589, 4940, 5005, 5499, 5850, 5941, 6006, 6760, 6851, 6942, 7007, 7670, 7761, 7852, 7943, 8008, 8580, 8671
Offset: 1
1495 and 5941 are both multiples of 13.
-
Select[13*Range[0,700],Divisible[FromDigits[Reverse[IntegerDigits[ #]]],13]&] (* Harvey P. Dale, Nov 30 2014 *)
-
isok(n) = !(n % 13) && !(fromdigits(Vecrev(digits(n))) % 13); \\ Michel Marcus, Aug 14 2018
A283737
Numbers with digit sum 13 that are multiples of 13.
Original entry on oeis.org
247, 364, 481, 715, 832, 1066, 1183, 1417, 1534, 1651, 2119, 2236, 2353, 2470, 2704, 2821, 3055, 3172, 3406, 3523, 3640, 4108, 4225, 4342, 4810, 5044, 5161, 5512, 6214, 6331, 7033, 7150, 7501, 8203, 8320, 9022, 10075, 10192, 10309, 10426, 10543, 10660, 11128, 11245
Offset: 1
a(1) = A143164(16) = 247 = 19*13,
a(90) = A143164(1186) = 25402 = 1954*13.
-
With[{k = 13}, Select[Range@ 12000, Total@ IntegerDigits@ # == k && Divisible[#, k] &]] (* Michael De Vlieger, Mar 16 2017 *)
-
for(k=1,1000,if(13==sumdigits(m=13*k),print1(m",")))
A309131
Triangle read by rows: T(n, k) = (n - k)*prime(1 + k), with 0 <= k < n.
Original entry on oeis.org
2, 4, 3, 6, 6, 5, 8, 9, 10, 7, 10, 12, 15, 14, 11, 12, 15, 20, 21, 22, 13, 14, 18, 25, 28, 33, 26, 17, 16, 21, 30, 35, 44, 39, 34, 19, 18, 24, 35, 42, 55, 52, 51, 38, 23, 20, 27, 40, 49, 66, 65, 68, 57, 46, 29, 22, 30, 45, 56, 77, 78, 85, 76, 69, 58, 31
Offset: 1
The triangle T(n, k) begins:
---+-----------------------------------------------------
n\k| 0 1 2 3 4 5 6 7 8
---+-----------------------------------------------------
1 | 2
2 | 4 3
3 | 6 6 5
4 | 8 9 10 7
5 | 10 12 15 14 11
6 | 12 15 20 21 22 13
7 | 14 18 25 28 33 26 17
8 | 16 21 30 35 44 39 34 19
9 | 18 24 35 42 55 52 51 38 23
...
For n = 3 the matrix M(3) is
2, 3, 5
M_{2,1}, 2, 3
M_{3,1}, M_{3,2}, 2
and therefore T(3, 0) = 2 + 2 + 2 = 6, T(3, 1) = 3 + 3 = 6, and T(3, 2) = 5.
-
[[(n-k)*NthPrime(1+k): k in [0..n-1]]: n in [1..11]]; // triangle output
-
a:=(n, k)->(n-k)*ithprime(1+k): seq(seq(a(n, k), k=0..n-1), n=1..11);
-
Flatten[Table[(n-k)*Prime[1+k],{n,1,11},{k,0,n-1}]]
-
T(n, k) = (n - k)*prime(1 + k);
tabl(nn) = for(n=1, nn, for(k=0, n-1, print1(T(n, k), ", ")); print); \\ triangle output
-
[[(n-k)*Primes().unrank(k) for k in (0..n-1)] for n in (1..11)] # triangle output
A098961
Sums of two squares and divisible by 13.
Original entry on oeis.org
13, 26, 52, 65, 104, 117, 130, 169, 208, 221, 234, 260, 325, 338, 377, 416, 442, 468, 481, 520, 533, 585, 637, 650, 676, 689, 754, 793, 832, 845, 884, 936, 949, 962, 1040, 1053, 1066, 1105, 1157, 1170, 1261, 1274, 1300, 1313
Offset: 1
Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Oct 22 2004
Sums not divisible by 13 are shown in asterisks:
.
| 1 4 9 16 25 36 49 64 81 100 121
----+------------------------------------------------------
1 | * * * * 26 * * 65 * * *
4 | * * 13 * * * * * * 104 *
9 | * 13 * * * * * * * * 130
16 | * * * * * 52 65 * * * *
25 | 26 * * * * * * * * * *
36 | * * * 52 * * * * 117 * *
49 | * * * 65 * * * * 130 * *
64 | 65 * * * * * * * * * *
81 | * * * * * 117 130 * * * *
100 | * 104 * * * * * * * * 221
121 | * * 130 * * * * * * 221 *
-
filter:= proc(n) local t,F;
F:= select(t -> t[2]::odd, ifactors(n)[2]);
andmap(t -> t[1] = 2 or t[1] mod 4 = 1, F);
end proc:
select(filter, [seq(i,i=13..10000, 13)]); # Robert Israel, Dec 02 2022
-
With[{nn=50},Take[Union[Select[Total/@Subsets[Range[nn]^2,{2}], Divisible[ #,13]&]],nn]] (* Harvey P. Dale, Aug 15 2014 *)
A101492
Triangle read by rows: T(n,k) = (n-k+1)*(4*k+1).
Original entry on oeis.org
1, 2, 5, 3, 10, 9, 4, 15, 18, 13, 5, 20, 27, 26, 17, 6, 25, 36, 39, 34, 21, 7, 30, 45, 52, 51, 42, 25, 8, 35, 54, 65, 68, 63, 50, 29, 9, 40, 63, 78, 85, 84, 75, 58, 33, 10, 45, 72, 91, 102, 105, 100, 87, 66, 37, 11, 50, 81, 104, 119, 126, 125, 116, 99, 74, 41, 12, 55, 90, 117
Offset: 0
Row sums give hexagonal pyramidal numbers
A002412.
-
Flat(List([0..11],n->List([0..n],k->(n+1-k)*(4*k+1)))); # Muniru A Asiru, Mar 07 2019
-
[[(n+1-k)*(4*k+1): k in [0..n]]: n in [0..10]]; // G. C. Greubel, Mar 07 2019
-
Flatten[Table[(n+1-k)(4k+1),{n,0,15},{k,0,n}]] (* Harvey P. Dale, Jun 09 2011 *)
-
T(n, k) = if(k>n,0,(n-k+1)*(4*k+1));
for(i=0,10, for(j=0,i,print1(T(i,j),", "));print())
-
[[(n-k+1)*(4*k+1) for k in (0..n)] for n in (0..10)] # G. C. Greubel, Mar 07 2019
A199799
Totatives of 111111.
Original entry on oeis.org
1, 2, 4, 5, 8, 10, 16, 17, 19, 20, 23, 25, 29, 31, 32, 34, 38, 40, 41, 43, 46, 47, 50, 53, 58, 59, 61, 62, 64, 67, 68, 71, 73, 76, 79, 80, 82, 83, 85, 86, 89, 92, 94, 95, 97, 100, 101, 103, 106, 107, 109, 113, 115, 116, 118, 122, 124, 125, 127, 128, 131, 134
Offset: 1
-
a199799 n = a199799_list !! (n-1)
a199799_list = [x | x <- [1..111111], gcd x 111111 == 1]
-
Select[Range[200],CoprimeQ[#,111111]&] (* Paolo Xausa, Sep 27 2023 *)
A166397
Multiples of 13 whose reversal - 1 is also a multiple of 13.
Original entry on oeis.org
156, 247, 338, 429, 1560, 1651, 1742, 1833, 1924, 2470, 2561, 2652, 2743, 2834, 2925, 3380, 3471, 3562, 3653, 3744, 3835, 3926, 4290, 4381, 4472, 4563, 4654, 4745, 4836, 4927, 5291, 5382, 5473, 5564, 5655, 5746, 5837, 5928, 6292, 6383, 6474, 6565, 6656
Offset: 1
-
Select[13Range[700],Divisible[FromDigits[Reverse[IntegerDigits[#]]] -1, 13]&] (* Harvey P. Dale, Apr 23 2011 *)
Comments