A128947 Main diagonal of polygonal lucky array defined in A128511.
1, 9, 477, 2415, 2059, 2133, 651, 2835, 14935, 23529, 35721, 58311, 27105, 24013, 167775, 49375, 92925, 193305, 273105, 238855, 850155, 94209, 395901, 1055241, 310233, 387001, 1492839, 540765, 731025, 2172081, 934431, 835621
Offset: 1
Examples
Array begins: k..|.n-th lucky number which is also a (k+3)-gonal number 0..|.1...3...15....21...105...171...231...741...903..1275. 1..|.1...9...25....49...169...289...361...529...729...841. 2..|.1..51..477...651...925..2625..5551..6501..9801.17767. 3..|.1..15..231..2415..3003..3655..5151.10585.11781.13695. 4..|.1...7..189...235..2059..6175..8037..9211.17935.23377. 5..|.1..21..133...645..1281..2133..2821..4033..4485..7701. 6..|.1...9...75...111...261...559...651..1491..1639..2125. 7..|.1.297..451...855..1105..1387..1701..2835..4257..5967.
Programs
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PARI
findpl(vl, n) = {nb = 0; for (i=1, #vl, if (ispolygonal(vl[i], n+2), nb++; if (nb == n, return (vl[i]))););} lista(nn) = {vl = readvec("b000959.log"); for (n=1, nn, print1(findpl(vl, n), ", "););} \\ Michel Marcus, Mar 04 2014
Extensions
More terms from R. J. Mathar, Jun 07 2007
6 more terms via b000959.txt from R. J. Mathar, Oct 22 2010
a(21)-a(32) via b000959.txt from Michel Marcus, Mar 04 2014
Comments