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.

Previous Showing 21-27 of 27 results.

A147837 a(n)=7*a(n-1)-5*a(n-2), a(0)=1, a(1)=5.

Original entry on oeis.org

1, 5, 30, 185, 1145, 7090, 43905, 271885, 1683670, 10426265, 64565505, 399827210, 2475962945, 15332604565, 94948417230, 587975897785, 3641089198345, 22547744899490, 139628768304705, 864662653635485, 5354494733924870, 33158149869296665, 205334575415452305
Offset: 0

Views

Author

Philippe Deléham, Nov 14 2008

Keywords

Crossrefs

Cf. A147703.

Programs

  • Mathematica
    LinearRecurrence[{7,-5},{1,5},30] (* Harvey P. Dale, Oct 10 2015 *)

Formula

a(n) = Sum_{k=0..n} A147703(n,k)*4^k.
G.f.: (1-2*x)/(1-7*x+5*x^2).
a(n) = ((29+3*sqrt(29))/58)*(3.5+0.5*sqrt(29))^n +((29-3*sqrt(29))/58)*(3.5-0.5*sqrt(29))^n. - Richard Choulet, Nov 20 2008 [corrected by Jason Yuen, Oct 04 2024]

A147839 a(n)=9*a(n-1)-7*a(n-2), a(0)=1, a(1)=7 .

Original entry on oeis.org

1, 7, 56, 455, 3703, 30142, 245357, 1997219, 16257472, 132336715, 1077228131, 8768696174, 71377668649, 581018144623, 4729519621064, 38498549577215, 313380308847487, 2550932932586878, 20764734231349493, 169026077554037291
Offset: 0

Views

Author

Philippe Deléham, Nov 14 2008

Keywords

Programs

  • Mathematica
    LinearRecurrence[{9,-7},{1,7},30] (* Harvey P. Dale, Nov 30 2019 *)

Formula

a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*6^k . G.f.: (1-2x)/(1-9x+7*x^2).
a(n)= ((53+5*sqrt(53))/106)*(4.5+0.5*sqrt(53))^n + ((53-5*sqrt(53))/106)*(4.5-0.5*sqrt(53))^n [From Richard Choulet, Nov 20 2008]

A147840 a(n)=10*a(n-1)-8*a(n-2), a(0)=1, a(1)=8 .

Original entry on oeis.org

1, 8, 72, 656, 5984, 54592, 498048, 4543744, 41453056, 378180608, 3450181632, 31476371456, 287162261504, 2619811643392, 23900818341888, 218049690271744, 1989290355982336, 18148506037649408, 165570737528635392
Offset: 0

Views

Author

Philippe Deléham, Nov 14 2008

Keywords

Comments

a(n) = sum_{k=0..n} 2^n*binomial(n,k)*A007482(k) = 2^n*A052913(n). - R. J. Mathar, Oct 15 2012

Programs

  • Mathematica
    LinearRecurrence[{10,-8},{1,8},20] (* Harvey P. Dale, Dec 02 2021 *)

Formula

a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*7^k . G.f.: (1-2x)/(1-10x+8*x^2).
a(n)= ((17+3*sqrt(17))/34)*(5+sqrt(17))^n + ((17-3*sqrt(17))/34)*(5-sqrt(17))^n [From Richard Choulet, Nov 20 2008]
G.f.: (1-2x)/(1-10x+8x^2). - Harvey P. Dale, Dec 02 2021

A152599 a(n) = 10*a(n-1) - 12*a(n-2) for n > 1; a(0) = 1, a(1) = 4 .

Original entry on oeis.org

1, 4, 28, 232, 1984, 17056, 146752, 1262848, 10867456, 93520384, 804794368, 6925699072, 59599458304, 512886194176, 4413668442112, 37982050091008, 326856479604736, 2812780194955264, 24205524194295808, 208301879603494912, 1792552505703399424, 15425902501792055296
Offset: 0

Views

Author

Philippe Deléham, Dec 09 2008

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{10, -12}, {1, 4}, 25] (* Paolo Xausa, Jan 19 2024 *)

Formula

G.f.: (1-6*x)/(1-10*x+12*x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*3^(n-k).
a(n) = 2^n*A052961(n). - R. J. Mathar, Jun 14 2016

A152620 a(n)=-8*a(n-1)-6*a(n-2), n>1 ; a(0)=1, a(1)=-2 .

Original entry on oeis.org

1, -2, 10, -68, 484, -3464, 24808, -177680, 1272592, -9114656, 65281696, -467565632, 3348834880, -23985285248, 171789272704, -1230402470144, 8812484124928, -63117458178560, 452064760678912, -3237813336359936
Offset: 0

Views

Author

Philippe Deléham, Dec 10 2008

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{-8,-6},{1,-2},30] (* Harvey P. Dale, Apr 03 2015 *)

Formula

G.f.: (1+6*x)/(1+8*x+6*x^2). a(n)=Sum_{k, 0<=k<=n}A147703(n,k)*(-3)^(n-k).

A206831 Triangle T(n,k), read by rows, given by (1, -2, 1, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.

Original entry on oeis.org

1, 1, 1, -1, 0, 1, -1, -3, -1, 1, 1, 0, -4, -2, 1, 1, 5, 4, -4, -3, 1, -1, 0, 9, 10, -3, -4, 1, -1, -7, -9, 9, 17, -1, -5, 1, 1, 0, -16, -28, 2, 24, 2, -6, 1, 1, 9, 16, -16, -54, -14, 30, 6, -7, 1, -1, 0, 25, 60, 10
Offset: 0

Views

Author

Philippe Deléham, Feb 13 2012

Keywords

Comments

Riordan array ((1+x)/(1+x^2), x*(1-x)/(1+x^2)).
Antidiagonal sums are A010892(n).

Examples

			Triangle begins :
1
1, 1
-1, 0, 1
-1, -3, -1, 1
1, 0, -4, -2, 1
1, 5, 4, -4, -3, 1
-1, 0, 9, 10, -3, -4, 1
-1, -7, -9, 9, 17, -1, -5, 1
1, 0, -16, -28, 2, 24, 2, -6, 1
1, 9, 16, -16, -54, -14, 30, 6, -7, 1
-1, 0, 25, 60, 10, -80, -40, 34, 11, -8, 1
		

Crossrefs

Programs

  • Mathematica
    nmax=10; Flatten[CoefficientList[Series[CoefficientList[Series[(1 + x)/(1 - y*x + (1 + y)*x^2), {x, 0, nmax}], x], {y, 0, nmax}], y]] (* Indranil Ghosh, Mar 10 2017 *)

Formula

T(n,k) = T(n-1,k-1) - T(n-2,k) - T(n-2,k-1), n>1.
G.f.: (1+x)/(1-y*x+(1+y)*x^2).
Sum_{k, 0<=k<=n} T(n,k)*x^k = A000007(n), A057077(n), (-1)^n*A078050(n) for x = -1, 0, 1 respectively.

A199479 Triangle T(n,k), read by rows, given by (1,0,0,0,0,0,0,0,0,0,...) DELTA (1,1,1,0,0,0,0,0,0,0,...) where DELTA is the operator defined in A084938.

Original entry on oeis.org

1, 1, 1, 1, 3, 2, 1, 5, 9, 5, 1, 7, 20, 27, 13, 1, 9, 35, 73, 80, 34, 1, 11, 54, 151, 252, 234, 89, 1, 13, 77, 269, 597, 837, 677, 233, 1, 15, 104, 435, 1199, 2225, 2702, 1941, 610, 1, 17, 135, 657, 2158, 4956, 7943, 8533, 5523, 1597
Offset: 0

Views

Author

Philippe Deléham, Nov 06 2011

Keywords

Comments

Mirror image of triangle in A147703.

Examples

			Triangle begins:
  1;
  1,  1;
  1,  3,  2;
  1,  5,  9,  5;
  1,  7, 20, 27, 13;
  1,  9, 35, 73, 80, 34;
		

Crossrefs

Formula

Sum_{k=0..n} T(n,k)*x^k = A152620(n), A152594(n), A000007(n), A000012(n), A006012(n), A152596(n), A152599(n) for x=-3,-2,-1,0,1,2,3 respectively.
T(n,n) = A001519(n).
G.f.: (1-2y*x)/(1-(1+3y)*x+y*(1+y)*x^2).
Previous Showing 21-27 of 27 results.