A323585
Third Moebius transform of A000219. Number of plane partitions of n whose multiset of rows is aperiodic and whose multiset of columns is also aperiodic and whose parts are relatively prime.
Original entry on oeis.org
1, 1, 0, 3, 7, 21, 30, 83, 129, 267, 428, 856, 1332, 2482, 3909, 6798, 10853, 18331, 28665, 47327, 73829, 118527, 183898, 290780, 446508, 695964, 1061290, 1631829, 2470970, 3759609, 5646952, 8512306, 12700005, 18972387, 28120953, 41690725, 61392966, 90379781
Offset: 0
The a(4) = 7 plane partitions with aperiodic multisets of rows and columns and relatively prime parts:
31 211
.
3 21 111
1 1 1
.
2 11
1 1
1 1
The same for a(5) = 21:
41 32 311 221 2111
.
4 3 31 21 22 21 211 111 1111
1 2 1 2 1 11 1 11 1
.
3 2 21 11 111
1 2 1 11 1
1 1 1 1 1
.
2 11
1 1
1 1
1 1
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];
ptnplane[n_]:=Union[Map[Reverse@*primeMS,Join@@Permutations/@facs[n],{2}]];
Table[Sum[Length[Select[ptnplane[Times@@Prime/@y],And[GCD@@Length/@Split[#]==1,GCD@@Length/@Split[Transpose[PadRight[#]]]==1,And@@GreaterEqual@@@#,And@@(GreaterEqual@@@Transpose[PadRight[#]])]&]],{y,Select[IntegerPartitions[n],GCD@@#==1&]}],{n,10}]
Original entry on oeis.org
2, 1, 4, 4, 13, 14, 36, 48, 96, 141, 261, 386, 676, 1030, 1706, 2619, 4230, 6462, 10219, 15568, 24165, 36627, 56103, 84428, 127873, 191201, 286663, 425802, 632973, 933995, 1377774, 2020424, 2959438, 4314109, 6278824, 9100908, 13167388, 18983295, 27313916, 39177636, 56080228, 80048942, 114030110, 162018938, 229741517, 325000341, 458854803, 646409612
Offset: 0
- G. Almkvist, The differences of the number of plane partitions, Manuscript, circa 1991.
-
Differences[CoefficientList[Series[Product[(1-x^k)^-k, {k,1,64}], {x,0,64}],x],2] (* Harvey P. Dale, Jun 19 2011 *)
nmax = 50; Drop[CoefficientList[Series[(1-x)^2 * Product[1/(1-x^k)^k, {k, 1, nmax}], {x, 0, nmax}], x], 2] (* Vaclav Kotesovec, Oct 30 2016 *)
Original entry on oeis.org
-1, 3, 0, 9, 1, 22, 12, 48, 45, 120, 125, 290, 354, 676, 913, 1611, 2232, 3757, 5349, 8597, 12462, 19476, 28325, 43445, 63328, 95462, 139139, 207171, 301022, 443779, 642650, 939014, 1354671, 1964715, 2822084, 4066480, 5815907, 8330621, 11863720, 16902592, 23968714, 33981168, 47988828, 67722579, 95258824, 133854462, 187554809, 262483024, 366425586
Offset: 0
- G. Almkvist, The differences of the number of plane partitions, Manuscript, circa 1991.
-
nmax = 50; Drop[CoefficientList[Series[(1-x)^3 * Product[1/(1-x^k)^k, {k, 1, nmax}], {x, 0, nmax}], x], 3] (* Vaclav Kotesovec, Oct 30 2016 *)
Original entry on oeis.org
2, 4, 11, 30, 32, 40, 50, 85, 100, 237, 381, 733, 805, 882, 1015, 1650, 2439, 3163, 3335, 3506, 3675, 4152, 4446, 4576, 5010, 5101, 6045, 6760, 7412, 8178, 8562, 10026, 10527, 10888, 12406, 12693, 13479, 16109, 16978, 17962, 20696, 22483, 25383, 31458, 38956
Offset: 1
11 is in the sequence because A000219(11) = 859 is prime.
A089300
Number of planar partitions of n (A000219) that are non-squashing along rows and down columns (cf. A018819).
Original entry on oeis.org
1, 1, 3, 4, 9, 13, 25, 33, 56, 76, 122, 170, 264, 360, 538, 707, 1002, 1332, 1853, 2409, 3294
Offset: 0
E.g. a(4) = 9:
4.31.3.22.2.211.21..2..11
.....1....2.....1...1..11
....................1....
Original entry on oeis.org
1, 0, 0, 0, 1, 4, 15, 40, 103, 238, 531, 1131, 2362, 4811, 9694, 19307, 38243, 75400, 148443, 291984, 574724, 1132368, 2234617, 4416937, 8745567, 17343737, 34446090, 68500682, 136374947, 271755878, 541950747, 1081467319, 2159170372, 4312555339, 8616279482, 17219151572, 34418065540, 68805730450, 137566021077
Offset: 0
a(8) = 103 because A011782(8) + A000219(8) - A000712(8) = 128 + 160 - 185.
-
N=66; x='x+O('x^N);
gf011782 =(1-x)/(1-2*x);
gf000219 = 1/prod(n=1,N, (1-x^n)^n );
gf000712 = 1/eta(x)^2;
Vec( gf011782 + gf000219 - gf000712 )
\\ Joerg Arndt, Mar 25 2014
A162453
Plane partition triangle, row sums = A000219; derived from the Euler transform of [1, 2, 3, ...].
Original entry on oeis.org
1, 1, 2, 1, 2, 3, 1, 5, 3, 4, 1, 5, 9, 4, 5, 1, 9, 15, 12, 5, 6, 1, 9, 24, 24, 15, 6, 7, 1, 14, 36, 46, 30, 18, 7, 8, 1, 14, 58, 70, 65, 36, 21, 8, 9, 1, 20, 76, 130, 110, 78, 42, 24, 9, 10, 1, 20, 111, 196, 200, 144, 91, 48, 27, 10, 11, 1, 27, 150, 314, 335, 273, 168, 104, 54, 30
Offset: 1
First few rows of the array:
1, 1, 1, 1, 1, 1, ...; = a
1, 1, 3, 3, 6, 6, ...; = a*b
1, 1, 3, 6, 9, 15, ...; = a*b*c
1, 1, 3, 6, 13, 19, ...; = a*b*c*d
1, 1, 3, 6, 13, 24, ...; = a*b*c*d*e
...
then taking finite differences from the top and discarding the first "1" we obtain:
1;
1, 2;
1, 2, 3;
1, 5, 3, 4;
1, 5, 9, 4, 5;
1, 9, 15, 12, 5, 6;
1, 9, 24, 24, 15, 6, 7;
1, 14, 36, 46, 30, 18, 7, 8;
1, 14, 58, 70, 65, 36, 21, 8, 9;
1, 20, 76, 130, 110, 78, 42, 24, 9, 10;
1, 20, 111, 196, 200, 144, 91, 48, 27, 10, 11;
1, 27, 150, 314, 335, 273, 168, 104, 54, 30, 11, 12;
...
A294086
Numbers k such that k divides the number of planar partitions of k (A000219).
Original entry on oeis.org
1, 3, 6, 8, 10, 281, 382, 590, 5135, 13897, 31387, 37045, 46199, 85057
Offset: 1
281 is in the sequence because A000219(281) = 126261896396707768167577329446424334 is divisible by 281.
-
pp[0] = 1; pp[n_] := pp[n] = (1/n)*Sum[pp[n-k]*DivisorSigma[2, k], {k, 1, n}]; Reap[For[n = 0; k = 1, k < 10^5, k++, If[Divisible[pp[k], k], n++; Print["a(", n, ") = ", k, " pp(", k, ") = ", pp[k]]; Sow[k]]]][[2, 1]] (* Jean-François Alcover, Feb 11 2018 *)
Original entry on oeis.org
0, 1, 3, 8, 19, 43, 91, 187, 369, 711, 1335, 2459, 4442, 7904, 13851, 23965, 40958, 69248, 115872, 192097, 315652, 514485, 832112, 1336214, 2131099, 3377178, 5319290, 8330147, 12973662, 20100411, 30986772, 47542096, 72609729, 110410791, 167186826, 252138816, 378781852
Offset: 0
-
b:= proc(n) option remember; `if`(n=0, 1,
add(b(n-j)*numtheory[sigma][2](j), j=1..n)/n)
end:
a:= n-> add(b(n-j)*j, j=0..n):
seq(a(n), n=0..42); # Alois P. Heinz, Feb 09 2023
-
nmax = 50; CoefficientList[Series[x/(1-x)^2 * Product[1/(1 - x^k)^k, {k, 1, nmax}], {x, 0, nmax}], x]
A000027
The positive integers. Also called the natural numbers, the whole numbers or the counting numbers, but these terms are ambiguous.
Original entry on oeis.org
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77
Offset: 1
- T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 1.
- T. M. Apostol, Modular Functions and Dirichlet Series in Number Theory, Springer-Verlag, 1990, page 25.
- John H. Conway and Richard K. Guy, The Book of Numbers, New York: Springer-Verlag, 1996. See p. 22.
- W. Fulton and J. Harris, Representation theory: a first course, (1991), page 149. [From Leonid Bedratyuk, Jan 04 2010]
- I. S. Gradstein and I. M. Ryshik, Tables of series, products, and integrals, Volume 1, Verlag Harri Deutsch, 1981.
- R. E. Schwartz, You Can Count on Monsters: The First 100 numbers and Their Characters, A. K. Peters and MAA, 2010.
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
- N. J. A. Sloane, Table of n, a(n) for n = 1..500000 [a large file]
- Archimedes Laboratory, What's special about this number?
- Affaire de Logique, Pick et Pick et Colegram (in French), No. 1051, 18-04-2018.
- Paul Barry, A Catalan Transform and Related Transformations on Integer Sequences, Journal of Integer Sequences, Vol. 8 (2005), Article 05.4.5.
- James Barton, The Numbers
- A. Berger and T. P. Hill, What is Benford's Law?, Notices, Amer. Math. Soc., 64:2 (2017), 132-134.
- A. Breiland, L. Oesper, and L. Taalman, p-Coloring classes of torus knots, Online Missouri J. Math. Sci., 21 (2009), 120-126.
- N. Brothers, S. Evans, L. Taalman, L. Van Wyk, D. Witczak, and C. Yarnall, Spiral knots, Missouri J. of Math. Sci., 22 (2010).
- C. K. Caldwell, Prime Curios
- Case and Abiessu, interesting number
- S. Crandall, notes on interesting digital ephemera
- O. Curtis, Interesting Numbers
- M. DeLong, M. Russell, and J. Schrock, Colorability and determinants of T(m,n,r,s) twisted torus knots for n equiv. +/-1(mod m), Involve, Vol. 8 (2015), No. 3, 361-384.
- Walter Felscher, Historia Matematica Mailing List Archive.
- P. Flajolet and R. Sedgewick, Analytic Combinatorics, 2009; see page 371.
- Robert R. Forslund, A logical alternative to the existing positional number system, Southwest Journal of Pure and Applied Mathematics, Vol. 1 1995 pp. 27-29.
- E. Friedman, What's Special About This Number?
- R. K. Guy, Letter to N. J. A. Sloane
- Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
- Kival Ngaokrajang, Illustration about relation to many other sequences, when the sequence is considered as a triangular table read by its antidiagonals. Additional illustrations when the sequence is considered as a centered triangular table read by rows.
- Mike Keith, All Numbers Are Interesting: A Constructive Approach
- Leonardo of Pisa [Leonardo Pisano], Illustration of initial terms, from Liber Abaci [The Book of Calculation], 1202 (photo by David Singmaster).
- Feihu Liu, Guoce Xin, and Chen Zhang, Ehrhart Polynomials of Order Polytopes: Interpreting Combinatorial Sequences on the OEIS, arXiv:2412.18744 [math.CO], 2024. See pp. 15, 24.
- Robert Munafo, Notable Properties of Specific Numbers.
- G. Pfeiffer, Counting Transitive Relations, Journal of Integer Sequences, Vol. 7 (2004), Article 04.3.2.
- R. Phillips, Numbers from one to thirty-one
- J. Striker, Dynamical Algebraic Combinatorics: Promotion, Rowmotion, and Resonance, Notices of the AMS, June/July 2017, pp. 543-549.
- G. Villemin's Almanac of Numbers, NOMBRES en BREF (in French)
- Eric Weisstein's World of Mathematics, Natural Number, Positive Integer, Counting Number Composition, Davenport-Schinzel Sequence, Idempotent Number, N, Smarandache Ceil Function, Whole Number, Engel Expansion, and Trinomial Coefficient
- Wikipedia, List of numbers, Interesting number paradox, and Floyd's triangle
- Robert G. Wilson v, English names for the numbers from 0 to 11159 without spaces or hyphens
- Robert G. Wilson v, American English names for the numbers from 0 to 100999 without spaces or hyphens
- Index entries for "core" sequences
- Index entries for sequences of the a(a(n)) = 2n family
- Index entries for sequences that are permutations of the natural numbers
- Index entries for related partition-counting sequences
- Index entries for linear recurrences with constant coefficients, signature (2,-1).
- Index to divisibility sequences
- Index entries for sequences related to Benford's law
Cf.
A026081 = integers in reverse alphabetical order in U.S. English,
A107322 = English name for number and its reverse have the same number of letters,
A119796 = zero through ten in alphabetical order of English reverse spelling,
A005589, etc. Cf.
A185787 (includes a list of sequences based on the natural number array
A000027).
Cf.
A038722 (mirrored when seen as triangle),
A056011 (boustrophedon).
-
a000027 = id
a000027_list = [1..] -- Reinhard Zumkeller, May 07 2012
-
print([n for n in 1:280]) # Paul Muljadi, Apr 09 2024
-
[ n : n in [1..100]];
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A000027 := n->n; seq(A000027(n), n=1..100);
-
Range@ 77 (* Robert G. Wilson v, Mar 31 2015 *)
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makelist(n, n, 1, 30); /* Martin Ettl, Nov 07 2012 */
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{a(n) = n};
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print join(", ", 1..280) # Paul Muljadi, May 29 2024
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def A000027(n): return n # Chai Wah Wu, May 09 2022
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1:100
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seq 1 100
Comments