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 1-8 of 8 results.

A196450 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

3, 6, 14, 30, 67, 146, 320, 706, 1550, 3403, 7481, 16443, 36131, 79399, 174500, 383499, 842796, 1852205, 4070612, 8945988, 19660603, 43208249, 94959144, 208692464, 458645240, 1007969053, 2215223460, 4868418432, 10699372182, 23514119454
Offset: 1

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Author

R. H. Hardin, Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's.
Column 2 of A196456.

Examples

			Some solutions for n=4:
..1..0....2..2....1..0....1..1....1..0....0..1....1..0....2..2....2..2....0..0
..1..0....2..2....1..0....0..0....2..2....2..2....2..2....2..2....2..2....0..0
..1..0....0..1....1..1....0..0....2..2....2..2....2..2....1..0....0..0....0..0
..1..0....0..1....0..1....1..1....0..0....0..1....0..1....1..0....1..1....1..1
		

Crossrefs

Cf. A196456.

Formula

Empirical: a(n) = 2*a(n-1) +3*a(n-3) -2*a(n-4) -3*a(n-5) -5*a(n-6) -a(n-7).
Empirical g.f.: x*(3 + 2*x^2 - 7*x^3 - 5*x^4 - 9*x^5 - x^6) / (1 - 2*x - 3*x^3 + 2*x^4 + 3*x^5 + 5*x^6 + x^7). - Colin Barker, May 09 2018

A196451 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

4, 14, 40, 131, 383, 1232, 3966, 12314, 38745, 122989, 386667, 1216157, 3839910, 12101854, 38109643, 120144068, 378709117, 1193259020, 3760674157, 11852918903, 37353389828, 117718989595, 371005905259, 1169236902187, 3684870558556
Offset: 1

Views

Author

R. H. Hardin Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's
Column 3 of A196456

Examples

			Some solutions for n=4
..0..0..1....1..0..1....0..0..0....0..2..2....1..1..0....0..0..0....0..2..2
..0..0..1....1..0..1....0..2..2....0..2..2....0..1..1....1..1..1....0..2..2
..2..2..1....1..2..2....0..2..2....0..1..1....0..2..2....1..1..1....0..0..0
..2..2..0....0..2..2....0..0..1....1..1..0....0..2..2....0..0..0....1..1..1
		

Formula

Empirical: a(n) = 4*a(n-1) -5*a(n-2) +15*a(n-3) -28*a(n-4) +13*a(n-5) -a(n-6) -8*a(n-7) +6*a(n-8) +12*a(n-9) -46*a(n-10) +27*a(n-11) -28*a(n-12) +83*a(n-13) -5*a(n-14) +25*a(n-15) -23*a(n-16) -4*a(n-18)

A196452 Number of n X 4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

5, 30, 131, 594, 2930, 15274, 76809, 380093, 1900745, 9527317, 47791454, 239934641, 1203634551, 6035457841, 30269130212, 151821524586, 761535367044, 3819934203741, 19160599201791, 96107073057178, 482062802792429, 2417986066816592, 12128437822354667, 60835368690467514
Offset: 1

Views

Author

R. H. Hardin, Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's.

Examples

			Some solutions for n=5:
..0..0..2..2....0..0..0..0....0..0..1..1....2..2..1..1....1..0..0..0
..0..0..2..2....0..0..0..0....2..2..2..0....2..2..0..0....1..0..0..0
..1..1..1..0....0..0..2..2....2..1..2..2....1..1..1..1....1..0..0..0
..1..2..2..0....0..0..2..2....2..0..0..2....0..0..2..2....1..2..2..0
..0..2..2..0....0..0..0..1....2..2..2..2....0..0..2..2....0..2..2..0
		

Crossrefs

Column 4 of A196456.

Formula

Empirical: a(n) = 7*a(n-1) -15*a(n-2) +38*a(n-3) -84*a(n-4) +194*a(n-5) -250*a(n-6) -1059*a(n-7) -66*a(n-8) -910*a(n-9) +1845*a(n-10) +25120*a(n-11) +10190*a(n-12) -38236*a(n-13) +68320*a(n-14) +10899*a(n-15) -251830*a(n-16) -12937*a(n-17) -47142*a(n-18) -553200*a(n-19) +69561*a(n-20) +533489*a(n-21) -1642449*a(n-22) -436401*a(n-23) +6042242*a(n-24) +3515060*a(n-25) -7528796*a(n-26) -1508098*a(n-27) +18034521*a(n-28) +1036374*a(n-29) -20794117*a(n-30) +15310099*a(n-31) +32164418*a(n-32) -19996088*a(n-33) -49523594*a(n-34) +23771811*a(n-35) +42630527*a(n-36) -14333853*a(n-37) -49762720*a(n-38) -5236367*a(n-39) +14631189*a(n-40) -2601831*a(n-41) -19899517*a(n-42) -5183657*a(n-43) -1258284*a(n-44) -3972327*a(n-45) -1773169*a(n-46) +2977093*a(n-47) +1341855*a(n-48) -2141053*a(n-49) -508619*a(n-50) -426819*a(n-51) -38656*a(n-52) -355272*a(n-53) +146662*a(n-54) -41336*a(n-55) +30846*a(n-56) -21828*a(n-57) +5950*a(n-58) -410*a(n-59) -213*a(n-60) -93*a(n-61) +26*a(n-62) +3*a(n-63) -2*a(n-64) for n>65.

A196453 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

8, 67, 383, 2930, 27320, 249402, 2032584, 15952022, 128543371, 1060801262, 8803139813, 72685286254, 596527548372, 4887671652328, 40110935638661, 329698087638675, 2710883854573401, 22279902843871853, 183037488877957616
Offset: 1

Views

Author

R. H. Hardin Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's
Column 5 of A196456

Examples

			Some solutions for n=4
..1..1..1..1..0....1..0..0..1..1....2..2..2..2..0....0..1..1..0..0
..0..0..0..1..1....1..1..1..1..0....2..0..0..2..0....0..1..2..2..0
..0..0..0..2..2....0..1..2..2..0....2..2..0..2..0....1..1..2..2..0
..1..1..1..2..2....0..1..2..2..0....0..2..2..2..1....1..0..0..0..0
		

A196454 Number of nX6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

12, 146, 1232, 15274, 249402, 3707781, 46887621, 578160718, 7394096617, 96338727461, 1258078944815, 16370595753240, 212274372772624, 2750178418606822, 35652972674573032, 462472339632802800
Offset: 1

Views

Author

R. H. Hardin Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's
Column 6 of A196456

Examples

			Some solutions for n=4
..2..2..2..2..2..0....0..0..1..1..0..0....0..0..2..2..1..0....1..0..0..1..2..2
..2..1..1..1..2..0....1..2..2..2..2..2....1..1..2..2..1..1....1..1..1..1..2..2
..2..0..0..0..2..0....1..2..0..0..1..2....2..2..0..0..0..1....0..2..2..0..1..1
..2..2..2..2..2..0....0..2..2..2..2..2....2..2..0..0..0..1....0..2..2..1..1..0
		

A196455 Number of n X 7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

17, 320, 3966, 76809, 2032584, 46887621, 926499600, 17962317556, 351103877665, 6945098996988, 139065692664815, 2795329197283554, 56072977068447935, 1121420878698363003, 22398808824228997399, 447457890891091698310
Offset: 1

Views

Author

R. H. Hardin, Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's.
Column 7 of A196456.

Examples

			Some solutions for n=4
..2..2..2..1..1..1..0....0..1..1..0..0..1..1....0..1..1..0..0..0..0
..2..0..2..0..0..2..2....0..2..2..2..2..2..0....2..2..1..0..0..0..0
..2..2..2..1..1..2..2....0..2..0..0..1..2..0....2..2..1..0..0..2..2
..0..0..0..1..1..0..0....1..2..2..2..2..2..1....0..0..1..1..1..2..2
		

Crossrefs

Cf. A196456.

A194657 Decimal expansion of (4*Pi^6*log(2) - 90*Pi^4*zeta(3) + 1350*Pi^2*zeta(5) - 5715*zeta(7))/1536.

Original entry on oeis.org

1, 1, 7, 5, 7, 5, 8, 3, 4, 0, 7, 2, 3, 3, 2, 4, 8, 2, 0, 6, 2, 4, 2, 9, 0, 6, 7, 9, 4, 9, 1, 4, 7, 5, 8, 4, 3, 3, 4, 1, 6, 4, 3, 8, 9, 9, 8, 1, 6, 2, 9, 0, 8, 8, 8, 6, 9, 5, 3, 0, 2, 4, 7, 6, 4, 9, 1, 9, 1, 2, 8, 4, 2, 7, 1, 5, 5, 9, 4, 7, 1, 1, 8, 2, 6, 8, 8, 8, 9, 0, 0, 3, 1, 4, 1, 1, 5, 9, 4, 4, 7, 1, 9, 9, 4
Offset: 0

Views

Author

Seiichi Kirikami, Sep 01 2011

Keywords

Comments

The absolute value of the integral {x=0..Pi/2} x^5*log(sin(x )) dx or (d^5/da^5 (integral {x=0..Pi/2} sin(ax)*log(sin(x )) dx)) at a=0. The absolute value of m=2 of (-1)^(m+1)*(sum {n=1..infinity} (limit {a -> 0} (d^(2m+1)/da^(2m+1) ((1-cos((a+2n)*Pi/2))/n/(a+2n)))))-(pi/2)^2(m+1)*log(2)/2/(m+1).

Examples

			0.11757583407233248206...
		

References

  • I. S. Gradshteyn and I. M. Ryzhik, Table of Integrals, Series and Products, 4th edition, 1.441.2

Crossrefs

Programs

  • Mathematica
    RealDigits[ N[(4 Pi^6*Log[2]-90 Pi^4*Zeta[3]+1350 Pi^2*Zeta[5]-5715 Pi^2*Zeta[7])/1536,150]][[1]]

Formula

Equals (4*A092732*A002162-90*A092425*A002117+1350*A002388*A013663-5715*A013665)/1536.

A196449 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,0,2,4,1 for x=0,1,2,3,4.

Original entry on oeis.org

1, 6, 40, 594, 27320, 3707781, 926499600, 539621963877, 739769209147928
Offset: 1

Views

Author

R. H. Hardin Oct 02 2011

Keywords

Comments

Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 4's, every 4 is next to 4 1's
Diagonal of A196456

Examples

			Some solutions for n=4
..1..0..0..1....1..0..0..0....1..0..0..1....1..0..0..1....1..0..0..1
..1..2..2..2....1..2..2..0....2..2..0..1....1..2..2..1....1..2..2..2
..0..2..0..2....0..2..2..0....2..2..0..1....0..2..2..0....0..2..0..2
..1..2..2..2....0..1..1..0....0..0..0..1....0..0..1..1....0..2..2..2
		
Showing 1-8 of 8 results.