A006431 -id:A006431 - cp's OEIS frontend

A295159 Smallest number with exactly n representations as a sum of five nonnegative squares.

0, 4, 13, 20, 29, 37, 50, 52, 61, 74, 77, 85, 91, 101, 106, 118, 125, 131, 133, 139, 162, 157, 154, 166, 178, 194, 187, 205, 203, 202, 227, 211, 226, 235, 234, 269, 251, 275, 250, 266, 291, 274, 259, 283, 301, 325, 306, 298, 326, 334, 347, 322, 362, 447, 331

Offset: 1

Robert Price, Nov 15 2017

nonn

Conjecture: a(448) does not exist, i.e., there is no number with exactly 448 such representations. - Robert Israel, Nov 15 2017

E. Grosswald, Representations of Integers as Sums of Squares. Springer-Verlag, New York, 1985, p. 86, Theorem 1.

Robert Israel, Table of n, a(n) for n = 1..447 (first 200 terms from Robert Price)
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.

Cf. A000174, A006431, A294675.

N:= 1000: # to get a(1)...a(n) where a(n+1) is the first term > N
V:= Array(0..N):
for x[1] from 0 to floor(sqrt(N/5)) do
  for x[2] from x[1] while x[1]^2 + 4*x[2]^2 <= N do
    for x[3] from x[2] while x[1]^2 + x[2]^2 + 3*x[3]^2 <= N do
      for x[4] from x[3] while x[1]^2 + x[2]^2 + x[3]^2 + 2*x[4]^2 <= N do
        for x[5] from x[4] while x[1]^2 + x[2]^2 + x[3]^2 + x[4]^2 + x[5]^2 <= N do
           t:=  x[1]^2 + x[2]^2 + x[3]^2 + x[4]^2 + x[5]^2;
           V[t]:= V[t]+1;
od od od od od:
A:= Vector(max(V),-1):
for i from 0 to N do if A[V[i]]=-1 then A[V[i]]:= i fi od:
T:= select(t -> A[t]=-1, [$1..max(V)]):
if T = [] then nmax:= max(V) else nmax:= T[1]-1 fi:
convert(A[1..nmax],list); # Robert Israel, Nov 15 2017

A000174(a(n))=n. - Robert Israel, Nov 15 2017

A293175 Integers with precisely six partitions into sums of four squares of nonnegative numbers.

Original entry on oeis.org

66, 81, 97, 99, 105, 110, 115, 121, 123, 124, 137, 139, 141, 149, 155, 156, 158, 159, 164, 179, 188, 239, 264, 284, 440, 496, 624, 632, 656, 752, 1056, 1136, 1760, 1984, 2496, 2528, 2624, 3008, 4224, 4544, 7040, 7936, 9984, 10112, 10496, 12032, 16896, 18176

Offset: 1

Robert Price, Oct 27 2017

nonn

A002635(a(n)) = 6.

D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.
Index entries for sequences related to sums of squares

Cf. A001156, A002635, A006431, A025428, A180149, A245022, A294282, A294297.

f[n_] := Length@ PowersRepresentations[n, 4, 2]; Select[ Range@ 19000, f@# == 6 &] (* Robert G. Wilson v, Oct 27 2017 *)

A294308 Integers with precisely seven partitions into sums of four squares of nonnegative numbers.

Original entry on oeis.org

82, 98, 100, 102, 106, 108, 118, 125, 129, 132, 133, 134, 135, 161, 163, 173, 183, 197, 199, 204, 211, 212, 215, 236, 263, 328, 392, 400, 408, 424, 432, 472, 528, 536, 816, 848, 944, 1312, 1568, 1600, 1632, 1696, 1728, 1888, 2112, 2144, 3264, 3392, 3776

Offset: 1

Robert Price, Oct 27 2017

nonn

A002635(a(n)) = 7.

Robert Price, Table of n, a(n) for n = 1..74
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.
Index entries for sequences related to sums of squares

Cf. A001156, A002635, A006431, A025428, A180149, A245022, A294282, A294297, A293175.

f[n_]:=Length@PowersRepresentations[n, 4, 2]; Select[Range@650, f@#==7 &] (* Vincenzo Librandi, Oct 28 2017 *)

A294310 Integers with precisely nine partitions into sums of four squares of nonnegative numbers.

Original entry on oeis.org

90, 146, 166, 174, 185, 187, 205, 206, 207, 209, 219, 220, 221, 223, 231, 235, 251, 260, 271, 287, 316, 359, 360, 380, 584, 664, 696, 824, 880, 1040, 1264, 1440, 1520, 2336, 2656, 2784, 3296, 3520, 4160, 5056, 5760, 6080, 9344, 10624, 11136, 13184, 14080

Offset: 1

Robert Price, Oct 27 2017

nonn

A002635(a(n)) = 9.

Robert Price, Table of n, a(n) for n = 1..60
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.
Index entries for sequences related to sums of squares

Cf. A001156, A002635, A006431, A025428, A180149, A245022, A294282, A294297.

f[n_]:=Length@PowersRepresentations[n, 4, 2]; Select[Range@850, f@#==9 &] (* Vincenzo Librandi, Oct 28 2017 *)

A294309 Integers with precisely eight partitions into sums of four squares of nonnegative numbers.

Original entry on oeis.org

114, 117, 122, 126, 145, 147, 148, 157, 165, 169, 172, 175, 177, 181, 190, 193, 203, 227, 233, 311, 456, 488, 504, 592, 688, 760, 1824, 1952, 2016, 2368, 2752, 3040, 7296, 7808, 8064, 9472, 11008, 12160, 29184, 31232, 32256, 37888, 44032, 48640

Offset: 1

Robert Price, Oct 27 2017

nonn

A002635(a(n)) = 8.

D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.
Index entries for sequences related to sums of squares

Cf. A001156, A002635, A006431, A025428, A180149, A245022, A294282, A294297.

f[n_]:=Length@PowersRepresentations[n, 4, 2]; Select[Range@850, f@#==8 &] (* Vincenzo Librandi, Oct 28 2017 *)

A294311 Integers with precisely ten partitions into sums of four squares of nonnegative numbers.

Original entry on oeis.org

130, 138, 153, 154, 171, 180, 182, 195, 196, 201, 213, 214, 217, 228, 229, 238, 241, 244, 247, 249, 253, 254, 257, 259, 269, 276, 277, 281, 295, 299, 303, 308, 317, 319, 332, 335, 347, 428, 431, 520, 552, 616, 720, 728, 784, 856, 912, 952, 976, 1016, 1104

Offset: 1

Robert Price, Oct 27 2017

nonn

A002635(a(n)) = 10.

Robert Price, Table of n, a(n) for n = 1..98
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.
Index entries for sequences related to sums of squares

Cf. A001156, A002635, A006431, A025428, A180149, A245022, A294282, A294297, A293175, A294308, A294309, A294310.

f[n_]:=Length@PowersRepresentations[n, 4, 2]; Select[Range@850, f@#==10 &] (* Vincenzo Librandi, Oct 28 2017 *)

A295153 Numbers that have exactly five representations as a sum of five nonnegative squares.

Original entry on oeis.org

29, 34, 35, 36, 38, 40, 41, 42, 44, 46, 55, 57

Offset: 1

Robert Price, Nov 15 2017

This sequence is finite and complete. See the von Eitzen Link and the proof in A294675 stating that for n > 5408, the number of ways to write n as a sum of 5 squares (without allowing zero squares) is at least floor(sqrt(n - 101) / 8) = 9. Since this sequence relaxes the restriction of zero squares, the number of representations for n > 5408 is at least nine. Then an inspection of n <= 5408 completes the proof.

E. Grosswald, Representations of Integers as Sums of Squares. Springer-Verlag, New York, 1985, p. 86, Theorem 1.

H. von Eitzen, in reply to user James47, What is the largest integer with only one representation as a sum of five nonzero squares? on stackexchange.com, May 2014
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.

Cf. A000174, A006431, A294675.

A019438 Squarefree orders of elements of Mathieu group M_23.

Original entry on oeis.org

1, 2, 3, 5, 6, 7, 11, 14, 15, 23

Offset: 0

N. J. A. Sloane

Numbers having a unique partition into four nonnegative squares. Let r=2, 6, or 14. Then the numbers r*4^k also have unique partitions into the four nonnegative squares for k>0. See A006431. - T. D. Noe, Aug 10 2005

D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No.8, October 1948, pp. 476-481.
G. Nebe and M. Teider, Hecke actions on certain strongly modular genera of lattices, Archiv der Mathematik 84 (1) (2005) 46-56.
E. M. Rains and N. J. A. Sloane, The Shadow Theory of Modular and Unimodular Lattices, J. Number Theory, 73 (1998), 359-389.

A295151 Numbers that have exactly three representations as a sum of five nonnegative squares.

Original entry on oeis.org

13, 16, 17, 18, 19, 21, 22, 30, 31, 33, 39

Offset: 1

Robert Price, Nov 15 2017

This sequence is finite and complete. See the von Eitzen Link and the proof in A294675 stating that for n > 5408, the number of ways to write n as a sum of 5 squares (without allowing zero squares) is at least floor(sqrt(n - 101) / 8) = 9. Since this sequence relaxes the restriction of zero squares, the number of representations for n > 5408 is at least nine. Then an inspection of n <= 5408 completes the proof.

E. Grosswald, Representations of Integers as Sums of Squares. Springer-Verlag, New York, 1985, p. 86, Theorem 1.

H. von Eitzen, in reply to user James47, What is the largest integer with only one representation as a sum of five nonzero squares? on stackexchange.com, May 2014
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.

Cf. A000174, A006431, A294675.

A295152 Numbers that have exactly four representations as a sum of five nonnegative squares.

Original entry on oeis.org

20, 25, 26, 27, 28, 32, 47, 48, 60

Offset: 1

Robert Price, Nov 15 2017

This sequence is finite and complete. See the von Eitzen Link and the proof in A294675 stating that for n > 5408, the number of ways to write n as a sum of 5 squares (without allowing zero squares) is at least floor(sqrt(n - 101) / 8) = 9. Since this sequence relaxes the restriction of zero squares, the number of representations for n > 5408 is at least nine. Then an inspection of n <= 5408 completes the proof.

E. Grosswald, Representations of Integers as Sums of Squares. Springer-Verlag, New York, 1985, p. 86, Theorem 1.

H. von Eitzen, in reply to user James47, What is the largest integer with only one representation as a sum of five nonzero squares? on stackexchange.com, May 2014
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.

Cf. A000174, A006431, A294675.

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A295159 Smallest number with exactly n representations as a sum of five nonnegative squares.

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A293175 Integers with precisely six partitions into sums of four squares of nonnegative numbers.

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A294308 Integers with precisely seven partitions into sums of four squares of nonnegative numbers.

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A294310 Integers with precisely nine partitions into sums of four squares of nonnegative numbers.

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A294309 Integers with precisely eight partitions into sums of four squares of nonnegative numbers.

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A294311 Integers with precisely ten partitions into sums of four squares of nonnegative numbers.

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A295153 Numbers that have exactly five representations as a sum of five nonnegative squares.

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A019438 Squarefree orders of elements of Mathieu group M_23.

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A295151 Numbers that have exactly three representations as a sum of five nonnegative squares.

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A295152 Numbers that have exactly four representations as a sum of five nonnegative squares.