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.
%I A228352 #33 Jan 10 2024 16:01:37 %S A228352 1,1,1,1,2,2,1,3,5,4,1,4,10,13,8,1,5,17,34,34,16,1,6,26,73,116,89,32, %T A228352 1,7,37,136,314,396,233,64,1,8,50,229,712,1351,1352,610,128,1,9,65, %U A228352 358,1418,3728,5813,4616,1597,256,1,10,82,529,2564,8781,19520,25012,15760,4181,512 %N A228352 Triangle read by rows, giving antidiagonals of an array of sequences representing the number of compositions of n when there are N types of ones (the sequences in the array begin (1, N, ...)). %C A228352 The array sequence beginning (1, N, ...) is such that a(n) in the sequence represents the numbers of compositions of n when there are N types of ones. %H A228352 Alois P. Heinz, <a href="/A228352/b228352.txt">Rows n = 1..141, flattened</a> %F A228352 Antidiagonals of an array in which a(n+2) = (N+1)*a(n+1) - (n-1)*a(n); with array sequences beginning (1, N, ...). %F A228352 Array sequence beginning (1, N, ...) is the binomial transform of the sequence in A073133 beginning (1, (N-1), ...). %F A228352 Given the first sequence of the array is (1, 1, 2, 4, 8, 16, ...), successive sequences are INVERT transforms of previous sequences. %F A228352 Array sequence beginning (1, N, ...) is such that a(n), n>1 is N*(a) + a(n-1) + a(n-2) + a(n-3) + a(n-4) + ... + a(0). %e A228352 Array sequence beginning (1, 3, 10, 34, 116, ...) is the binomial transform of (1, 2, 5, 12, 70, ...) in A073133. %e A228352 First few sequences in the array: %e A228352 1, 1, 2, 4, 8, 16, ...; = A011782 %e A228352 1, 2, 5, 13, 34, 89, ...; = A001519 %e A228352 1, 3, 10, 34, 116, 396, ...; = A007052 %e A228352 ... followed by A018902, A018903, A018904, the latter beginning (1, 6, ...). First few rows of the triangle: %e A228352 1; %e A228352 1, 1; %e A228352 1, 2, 2; %e A228352 1, 3, 5, 4; %e A228352 1, 4, 10, 13, 8; %e A228352 1, 5, 17, 34, 34, 16; %e A228352 1, 6, 26, 73, 116, 89, 32; %e A228352 1, 7, 37, 136, 314, 396, 233, 64; %e A228352 1, 8, 50, 229, 712, 1351, 1352, 610, 128; %e A228352 1, 9, 65, 358, 1418, 3728, 5813, 4616, 1597, 256; %e A228352 1, 10, 82, 529, 2564, 8781, 19520, 25012, 15760, 4181, 512; %e A228352 ... %p A228352 A:= proc(N, n) option remember; %p A228352 `if`(n=0, 1, N*A(N, n-1) +add(A(N, n-j), j=2..n)) %p A228352 end: %p A228352 seq(seq(A(d-n, n), n=0..d-1), d=1..11); # _Alois P. Heinz_, Aug 20 2013 %t A228352 A[k_, n_] := A[k, n] = If[n == 0, 1, k*A[k, n-1] + Sum[A[k, n-j], {j, 2, n}]]; Table[A[d-n, n], {d, 1, 11}, {n, 0, d-1}] // Flatten (* _Jean-François Alcover_, May 27 2016, after _Alois P. Heinz_ *) %Y A228352 Cf. A073133, A011782, A001519, A007052, A018902, A018903, A018904. %K A228352 nonn,tabl %O A228352 1,5 %A A228352 _Gary W. Adamson_, Aug 20 2013