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.

Showing 1-9 of 9 results.

A143710 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1+2+3, 2+2+5, 2+3+7, 2+3+3, 2+2+5, 11+2+2, 3+13+2, 7+3+5,..).

Original entry on oeis.org

6, 9, 12, 8, 9, 15, 18, 15, 23, 7, 23, 15, 36, 8, 9, 19, 11, 34, 38, 19, 24, 11, 42, 24, 18, 48, 53, 15, 10, 72, 9, 11, 10, 21, 68, 11, 16, 29, 90, 7, 68, 36, 15, 20, 81, 21, 28, 83, 8, 77, 45, 6, 37, 18, 85, 12, 126, 7, 29, 48, 34, 102, 10, 22, 28, 80, 26, 105, 11, 16, 9, 105, 123
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=7+3+5=15.
a(9)=2+4+17=23.
a(10)=2+3+2=7.
a(11)=19+2+2=23.
a(12)=5+3+7=15.
a(13)=2+11+23=36,
etc.
		

Crossrefs

Extensions

a(43) corrected by R. J. Mathar, Apr 14 2010

A143704 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5, ...) becomes ((1+2)*3, (2+2)*5, (2+3)*7, (2+3)*3, (2+2)*5, (11+2)*2, (3+13)*2, (7+3)*5, ...).

Original entry on oeis.org

9, 20, 35, 15, 20, 26, 32, 50, 102, 10, 42, 56, 299, 15, 14, 48, 28, 93, 72, 88, 95, 18, 185, 63, 45, 92, 430, 44, 25, 1175, 18, 18, 21, 38, 132, 30, 39, 190, 1829, 12, 132, 68, 54, 36, 938, 68, 52, 852, 15, 150, 200, 8, 286, 65, 324, 32, 3569, 12, 204, 135, 93, 200, 25, 40
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)  = ( 7 +  3) *  5 = 10*5 = 50;
a(9)  = ( 2 +  4) * 17 = 102;
a(10) = ( 2 +  3) *  2 =  10;
a(11) = (19 +  2) *  2 =  42;
a(12) = ( 5 +  3) *  7 =  56;
a(13) = ( 2 + 11) * 23 = 199;
etc.
		

Crossrefs

Programs

  • Maple
    g:= proc(n) local L; L:= sort(ifactors(n)[2],(s,t) -> s[1]Robert Israel, Nov 16 2019

Extensions

Corrected (199 replaced by 299, 60 replaced by 30, 549 replaced by 54 etc.) by R. J. Mathar, Apr 18 2010

A143711 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1*2*3, 2*2*5, 2*3*7, 2*3*3, 2*2*5, 11*2*2, 3*13*2, 7*3*5,..).

Original entry on oeis.org

6, 20, 42, 18, 20, 44, 78, 105, 136, 12, 76, 105, 506, 18, 20, 117, 28, 174, 310, 165, 170, 28, 222, 114, 78, 410, 903, 44, 30, 2162, 24, 28, 30, 68, 1378, 45, 66, 399, 3422, 12, 610, 186, 84, 130, 2211, 68, 138, 2485, 18, 292, 555, 8, 1463, 78, 632, 60, 6806, 12
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=7*3*5=105.
a(9)=2*4*17=136.
a(10)=2*3*2=12.
a(11)=19*2*2=76.
a(12)=5*3*7=105.
a(13)=2*11*23=506,
etc.
		

Crossrefs

Extensions

a(43) corrected by R. J. Mathar, Apr 14 2010

A143705 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes ((1+2)^3, (2+2)^5, (2+3)^7, (2+3)^3, (2+2)^5, (11+2)^2, (3+13)^2, (7+3)^5,..).

Original entry on oeis.org

27, 1024, 78125, 125, 1024, 169, 256, 100000, 16926659444736, 25, 441, 2097152, 41753905413413116367045797, 125, 49, 4096, 16384, 29791, 1296, 8589934592, 2476099, 81, 72759576141834259033203125, 9261, 3375
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=(7+3)^5=10^5=100000.
a(9)=(2+4)^17=6^17=16926659444736..
a(10)=(2+3)^2=5^2=25.
a(11)=(19+2)^2=21^2=441.
a(12)=(5+3)^7=8^7=2097152,
etc.
		

Crossrefs

Extensions

Corrected (161051 removed) and extended by R. J. Mathar, Apr 18 2010

A143706 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1*2+3, 2*2+5, 2*3+7, 2*3+3, 2*2+5, 11*2+2, 3*13+2, 7*3+5,..).

Original entry on oeis.org

5, 9, 13, 9, 9, 24, 41, 26, 25, 8, 40, 22, 45, 9, 12, 42, 11, 61, 157, 26, 39, 16, 43, 41, 29, 207, 64, 15, 11, 93, 11, 16, 13, 36, 691, 14, 25, 40, 117, 7, 307, 95, 20, 67, 100, 21, 71, 106, 9, 148, 116, 6, 144, 19, 162, 19, 165, 7, 52, 89, 61, 981, 11, 93, 49, 109, 97, 112
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=7*3+5=21+5=26.
a(9)=2*4+17=8+17=25.
a(10)=2*3+2=6+2=8.
a(11)=19*2+2=38+2=40.
a(12)=5*3+7=15+7=22.
a(13)=2*11+23=22+23=45,
etc.
		

Crossrefs

Extensions

Corrected (9 duplicated, 75 replaced by 20 etc.) by R. J. Mathar, Apr 18 2010

A143707 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1*(2+3), 2*(2+5), 2*(3+7), 2*(3+3), 2*(2+5), 11*(2+2), 3*(13+2), 7*(3+5),..).

Original entry on oeis.org

5, 14, 20, 12, 14, 44, 45, 56, 42, 10, 76, 50, 68, 12, 20, 78, 18, 145, 165, 70, 44, 28, 117, 44, 65, 215, 150, 26, 21, 140, 14, 28, 25, 68, 715, 24, 55, 154, 176, 10, 315, 155, 56, 75, 234, 38, 75, 390, 12, 150, 296, 8, 342, 32, 474, 35, 248, 10, 154, 92, 145, 1001, 21, 105
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=7*(3+5)=7*8=56.
a(9)=2*(4+17)=2*21=42.
a(10)=2*(3+2)=2*5=10.
a(11)=19*(2+2)=19*4=40.
a(12)=5*(3+7)=5*10=50.
a(13)=2*(11+23)=2*34=68,
etc.
		

Crossrefs

Extensions

Corrected (40 replaced by 76, 18 by 12, 90 by 70 etc.) by R. J. Mathar, Apr 18 2010

A143708 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1^(2+3), 2^(2+5), 2^(3+7), 2^(3+3), 2^(2+5), 11^(2+2), 3^(13+2), 7^(3+5),..).

Original entry on oeis.org

1, 128, 1024, 64, 128, 14641, 14348907, 5764801, 2097152, 32, 130321, 9765625, 17179869184, 64, 625, 4826809, 512, 20511149, 116415321826934814453125, 6103515625, 4194304, 2401, 4052555153018976267, 4194304, 371293
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=7^(3+5)=7^8=5764801.
a(9)=2^(4+17)=2^21=2097152.
a(10)=2^(3+2)=2^5=32.
a(11)=19^(2+2)=19^4=130321.
a(12)=5^(3+7)=5^10=9765625.
a(13)=2^(11+23)=2^34=17179869184,
etc.
		

Crossrefs

Extensions

More terms from R. J. Mathar, Apr 18 2010

A143709 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1^2+3, 2^2+5, 2^3+7, 2^3+3, 2^2+5, 11^2+2, 3^13+2, 7^3+5,..).

Original entry on oeis.org

4, 9, 15, 11, 9, 123, 1594325, 348, 33, 10, 363, 132, 2071, 11, 27, 2200, 11, 844, 4656612873077392578127, 136, 131077, 51, 46, 524291, 172, 45474735088646411895751953127, 2230, 15, 14, 8388655, 19, 51, 28, 291
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 13 2008

Keywords

Examples

			a(8)=7^3+5=343+5=348.
a(9)=2^4+17=16+17=43.
a(10)=2^3+2=8+2=10.
a(11)=19^2+2=361+2=363.
a(12)=5^3+7=125+7=132.
a(13)=2^11+23=2048+23=2071,
etc.
		

Crossrefs

Extensions

Corrected (15 replaced by 9, 43 by 33) and extended by R. J. Mathar, Apr 18 2010

A144190 (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, ...) becomes (0 mod 1, 2 mod 3, 2 mod 2, 5 mod 2, 3 mod 7, 2 mod 3, 3 mod 2, 2 mod 5, 11 mod 2, 2 mod 3, ...).

Original entry on oeis.org

0, 2, 0, 1, 3, 2, 1, 2, 1, 2, 1, 1, 1, 4, 2, 2, 0, 2, 1, 11, 2, 3, 0, 1, 1, 2, 1, 3, 1, 2, 1, 2, 1, 2, 2, 2, 3, 2, 5, 2, 7, 0, 2, 2, 2, 1, 1, 1, 2, 2, 1, 2, 1, 0, 5, 2, 1, 1, 29, 0, 3, 1, 1, 2, 2, 5, 2, 11, 0, 2, 1, 5, 1, 0, 2, 2, 3, 0, 2, 7, 2, 13, 2, 2, 0, 41, 0, 3, 5, 2, 3, 2, 11, 2, 2, 7, 0, 2, 1, 2, 1, 2, 1
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 20 2008

Keywords

Examples

			2 mod 3 = 1 = a(10),
13 mod 2 = 1 = a(11),
7 mod 3 = 1 = a(12),
5 mod 2 = 1 = a(13),
4 mod 17 = 4 = a(14),
2 mod 3 = 2 = a(15),
2 mod 19 = 2 = a(16),
2 mod 2 = 0 = a(17),
5 mod 3 = 2 = a(18),
7 mod 2 = 1 = a(19),
11 mod 23 = 11 = a(20), etc.
		

Crossrefs

Programs

  • Maple
    pflat := proc(nmax) local a, ifs, n, p, c ; a := [0,1] ; for n from 2 to nmax do ifs := ifactors(n)[2] ; for p in ifs do a := [op(a),op(1,p)] ; if op(2,p) > 1 then a := [op(a),op(2,p)] ; fi; od: od: a ; end: L := pflat(300) ; for n from 1 to nops(L)-2 by 2 do printf("%d,", op(n,L) mod op(n+1,L) ) ; end do: # R. J. Mathar, Apr 29 2010

Extensions

a(10), a(43) and perhaps others corrected by R. J. Mathar, Apr 29 2010
Showing 1-9 of 9 results.