cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A068041 Number of subsets of {1,2,3,...,n} that sum to 0 mod 20.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 6, 14, 26, 52, 103, 205, 410, 820, 1640, 3278, 6554, 13108, 26216, 52432, 104860, 209716, 419432, 838864, 1677728, 3355448, 6710888, 13421776, 26843552, 53687104, 107374192, 214748368, 429496736, 858993472, 1717986944
Offset: 0

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Author

Antti Karttunen, Feb 11 2002

Keywords

Crossrefs

20th row of A068009.

Formula

Empirical G.f.: (x-1)^2*(4*x^12+4*x^11-x^10-7*x^9-11*x^8-15*x^7-15*x^6-11*x^5-5*x^4-2*x^3+x+1) / ((2*x-1)*(2*x^5-1)). [Colin Barker, Dec 22 2012]

A068042 Number of subsets of {1,2,3,...,n} that sum to 0 mod 21.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 6, 14, 26, 49, 99, 197, 391, 782, 1564, 3123, 6244, 12490, 24970, 49940, 99880, 199738, 399472, 798940, 1597844, 3195684, 6391368, 12782668, 25565336, 51130664, 102261174, 204522354, 409044702, 818089110, 1636178220
Offset: 0

Views

Author

Antti Karttunen, Feb 11 2002

Keywords

Crossrefs

21st row of A068009.

Formula

Empirical G.f.: -(8*x^31 -8*x^28 +4*x^27 -2*x^26 -2*x^25 -6*x^24 +4*x^23 +4*x^22 +2*x^21 +2*x^20 +6*x^19 -8*x^18 -12*x^17 -5*x^16 +6*x^15 +10*x^14 +x^13 -x^12 +5*x^11 +x^10 -6*x^8 -2*x^7 -2*x^6 -x^5 -x^4 +3*x^3 +x^2 +x -1) / ((2*x -1)*(2*x^3 -1)*(2*x^7 -1)*(2*x^21 -1)). [Colin Barker, Dec 22 2012]

A068043 Number of subsets of {1,2,3,...,n} that sum to 0 mod 25.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 3, 10, 23, 43, 82, 164, 328, 656, 1312, 2622, 5243, 10486, 20972, 41945, 83887, 167773, 335546, 671092, 1342184, 2684360, 5368712, 10737422, 21474842, 42949682, 85899350, 171798690, 343597388, 687194782, 1374389558
Offset: 0

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Author

Antti Karttunen, Feb 11 2002

Keywords

Crossrefs

25th row of A068009.

Formula

Empirical G.f.: -(x -1) * (4*x^29 +4*x^28 +4*x^27 -4*x^24 -4*x^23 -4*x^22 -3*x^21 -2*x^20 -x^19 -x^18 -x^17 -2*x^16 +4*x^15 +10*x^14 +4*x^13 -4*x^12 -6*x^11 -8*x^10 -9*x^9 -4*x^8 +2*x^7 +5*x^6 +6*x^5 +3*x^4 +2*x^3 +x^2 -1) / ((2*x -1)*(2*x^5 -1)*(2*x^25 -1)). [Colin Barker, Dec 23 2012]

A068044 Number of subsets of {1,2,3,...,n} that sum to 0 mod 32.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 3, 14, 37, 71, 129, 253, 511, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824
Offset: 0

Views

Author

Antti Karttunen, Feb 11 2002

Keywords

Crossrefs

32nd row of A068009.

Formula

G.f.: -(2*x^15+5*x^14-5*x^13-13*x^12-3*x^11+9*x^10+8*x^9+x^8-x^7-x^6-x^5-x^4-x^3-x^2-x+1) / (2*x-1). Colin Barker, Dec 23 2012
Previous Showing 21-24 of 24 results.