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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A157072 Number of integer sequences of length n+1 with sum zero and sum of absolute values 46.

Original entry on oeis.org

2, 138, 5292, 142140, 2947590, 49858158, 712832792, 8832976488, 96648771870, 947399938870, 8416542780492, 68407265558268, 512700872216442, 3567168162771570, 23172711963346320, 141251698411654288, 811481822951916942, 4410812923746903558, 22762369531189431140
Offset: 1

Views

Author

R. H. Hardin, Feb 22 2009

Keywords

Crossrefs

Programs

Formula

a(n) = T(n,23); T(n,k) = Sum_{i=1..n} binomial(n+1, i)*binomial(k-1, i-1)*binomial(n-i+k, k).
From G. C. Greubel, Jan 25 2022: (Start)
a(n) = (n+1)*binomial(n+22, 23)*Hypergeometric3F2([-22, -n, 1-n], [2, -n-22], 1).
a(n) = (8233430727600/46!)*n*(n+1)*(29057685629025609672383529751884595200000000 + 79452183147274795032078126183088128000000000*n + 141714570491802789957788787173889146880000000*n^2 + 145059233577401185360645255317602854502400000*n^3 + 127311238631698355225728753712566590504960000*n^4 + 75715351658040622253223159728830038933504000*n^5 + 42877191833222765234078376290791889436672000*n^6 + 17200430297827490899524392276866711148298240*n^7 + 7044053985717499896347935293286272148242432*n^8 + 2056356540242318373959793917651894923345920*n^9 + 649440492446852015686988427724931399725056*n^10 + 144397972805007063337564416010542851069952*n^11 + 36667320366669588030104490299079773399040*n^12 + 6396965852709968433012959028877233569280*n^13 + 1345127187454407600202359730144941101312*n^14 + 187910794743597175883242789084896626944*n^15 + 33447938991896902409607083541643054848*n^16 + 3794396649208001585975013323140823680*n^17 + 581596730556665903213714682678333648*n^18 + 54086974909357210248192242794085176*n^19 + 7237583584021550113709859989257256*n^20 + 555028323889889756001001018844270*n^21 + 65573979319258648679066391179799*n^22 + 4158352352131928037710752254818*n^23 + 437873818310682613098943721859*n^24 + 22960062441581678852556730250*n^25 + 2172171883621041163474766945*n^26 + 93893204989495788867340350*n^27 + 8036153654616364534710453*n^28 + 284537563980038034430380*n^29 + 22164572970995075714214*n^30 + 636147121922304974388*n^31 + 45339923676136414270*n^32 + 1038127683748744820*n^33 + 68016631509831858*n^34 + 1212869363347796*n^35 + 73356699164562*n^36 + 981609846470*n^37 + 55012667347*n^38 + 519602314*n^39 + 27075279*n^40 + 160930*n^41 + 7821*n^42 + 22*n^43 + n^44).
G.f.: 2*x*(1 + 22*x + 484*x^2 + 5082*x^3 + 53361*x^4 + 355740*x^5 + 2371600*x^6 + 11265100*x^7 + 53509225*x^8 + 192633210*x^9 + 693479556*x^10 + 1964858742*x^11 + 5567099769*x^12 + 12724799472*x^13 + 29085255936*x^14 + 54534854880*x^15 + 102252852900*x^16 + 159059993400*x^17 + 247426656400*x^18 + 321654653320*x^19 + 418151049316*x^20 + 456164781072*x^21 + 497634306624*x^22 + 456164781072*x^23 + 418151049316*x^24 + 321654653320*x^25 + 247426656400*x^26 + 159059993400*x^27 + 102252852900*x^28 + 54534854880*x^29 + 29085255936*x^30 + 12724799472*x^31 + 5567099769*x^32 + 1964858742*x^33 + 693479556*x^34 + 192633210*x^35 + 53509225*x^36 + 11265100*x^37 + 2371600*x^38 + 355740*x^39 + 53361*x^40 + 5082*x^41 + 484*x^42 + 22*x^43 + x^44)/(1-x)^47. (End)

A157073 Number of integer sequences of length n+1 with sum zero and sum of absolute values 48.

Original entry on oeis.org

2, 144, 5762, 161480, 3493730, 61651128, 919453346, 11883194148, 135595653690, 1385919151540, 12835654787802, 108738668285884, 849286949294602, 6156408373152940, 41657479594194090, 264432781857156298, 1581589562174104296, 8947669593793415178
Offset: 1

Views

Author

R. H. Hardin, Feb 22 2009

Keywords

Crossrefs

Programs

Formula

a(n) = T(n,24); T(n,k) = Sum_{i=1..n} binomial(n+1, i)*binomial(k-1, i-1)*binomial(n-i+k, k).
From G. C. Greubel, Jan 27 2022: (Start)
a(n) = (n+1)*binomial(n+23, 24)*Hypergeometric3F2([-23, -n, 1-n], [2, -n-23], 1).
a(n) = (32247603683100/48!)*n*(n+1)*(16039842467222136539155708423040296550400000000 + 44525931866763275880171946837357992345600000000*n + 80162352992638760747141669078132808744960000000*n^2 + 83332132056036918488105323040316226063564800000*n^3 + 73898939901046923323215546964133115613675520000*n^4 + 44723032603767485653970945505703213072908288000*n^5 + 25612689570363639698514348299721610493952000000*n^6 + 10480812936564898576921267191518638010904084480*n^7 + 4344005319097142489606724072829615182825652224*n^8 + 1297122051885262240041808754289430257096523776*n^9 + 414887762782195453530600601421093882956775424*n^10 + 94644812314641495323136291475493075984289792*n^11 + 24355352682168634128406213057069994741673984*n^12 + 4374473519129303099715556660819067718420480*n^13 + 932704708306541825734118078032140866985984*n^14 + 134664684009917015892204293368196583403264*n^15 + 24318248584827829951503296783169426424064*n^16 + 2863809547176445630879170275831524932864*n^17 + 445554853840168519046977908135462996864*n^18 + 43232734952768495830917555723936691056*n^19 + 5874830266761134611938171223806383184*n^20 + 472840057219714797927879342154953928*n^21 + 56755099941609678328578532372768784*n^22 + 3803612022719773196434862241794913*n^23 + 407080783477921724014741379761599*n^24 + 22745052288898786827887020700757*n^25 + 2187954196667457627798376601499*n^26 + 101789002477485622214691512935*n^27 + 8861565620717173319451105401*n^28 + 341896269373157379303910179*n^29 + 27099899470126559155285701*n^30 + 860938389633999087289098*n^31 + 62459741766357695776566*n^32 + 1615864725980444668850*n^33 + 107800168679533475566*n^34 + 2233886413294116126*n^35 + 137618394169017186*n^36 + 2229052716036366*n^37 + 127282327855386*n^38 + 1552111826309*n^39 + 82428676891*n^40 + 711564777*n^41 + 35254791 n^42 + 192027*n^43 + 8901*n^44 + 23*n^45 + n^46).
G.f.: 2*x*(1 + 23*x + 529*x^2 + 5819*x^3 + 64009*x^4 + 448063*x^5 + 3136441*x^6 + 15682205*x^7 + 78411025*x^8 + 297961895*x^9 + 1132255201*x^10 + 3396765603*x^11 + 10190296809*x^12 + 24747863679*x^13 + 60101954649*x^14 + 120203909298*x^15 + 240407818596*x^16 + 400679697660*x^17 + 667799496100*x^18 + 934919294540*x^19 + 1308887012356*x^20 + 1546866469148*x^21 + 1828114918084*x^22 + 1828114918084*x^23 + 1828114918084*x^24 + 1546866469148*x^25 + 1308887012356*x^26 + 934919294540*x^27 + 667799496100*x^28 + 400679697660*x^29 + 240407818596*x^30 + 120203909298*x^31 + 60101954649*x^32 + 24747863679*x^33 + 10190296809*x^34 + 3396765603*x^35 + 1132255201*x^36 + 297961895*x^37 + 78411025*x^38 + 15682205*x^39 + 3136441*x^40 + 448063*x^41 + 64009*x^42 + 5819*x^43 + 529*x^44 + 23*x^45 + x^46)/(1-x)^49. (End)

A177326 Number of permutations of n copies of 1..5 with all adjacent differences <= 3 in absolute value.

Original entry on oeis.org

1, 72, 41580, 37850400, 42251309100, 52977847995072, 71614356453896256, 102038786510159790720, 151158246783053570131500, 230729955958244519983206000, 360656999876515853295073369080, 574739352751818771710077504838400, 930674941577730459521320183457601600
Offset: 0

Views

Author

R. H. Hardin, May 06 2010

Keywords

Crossrefs

Formula

a(n) = A103881(3n,n) * A006480(n). - Martin Fuller, Jun 08 2025

Extensions

a(0)=1 prepended by Martin Fuller, Jun 08 2025
Previous Showing 31-33 of 33 results.