%I A157221
%S A157221 1,1,1,1,4,1,1,11,11,1,1,26,14608,26,1,1,57,152637,152637,57,1,1,120,
%T A157221 1479726,251732291184,1479726,120,1,1,247,13824739,16871482830550,
%U A157221 16871482830550,13824739,247,1,1,502,126781020,1103881308184906
%N A157221 A Eulerian tent triangle sequence: tent function: f(n,m)=If[k <= Floor[n/
               2], k, n - k]; t(n,m)=Eulerian[n*f[n, m], f[n, m]].
%C A157221 Row sums are:
%C A157221 {1, 2, 6, 24, 14662, 305390, 251735250878, 33742993311074,
%C A157221 113909685422248854462458, 144084186112517513027508010,
%C A157221 4826601749538111416289955703874773044570,...}.
%F A157221 Tent function: f(n,m)=If[k <= Floor[n/2], k, n - k]; t(n,m)=Eulerian[n*f[n, 
               m], f[n, m]].
%e A157221 {1},
%e A157221 {1, 1},
%e A157221 {1, 4, 1},
%e A157221 {1, 11, 11, 1},
%e A157221 {1, 26, 14608, 26, 1},
%e A157221 {1, 57, 152637, 152637, 57, 1},
%e A157221 {1, 120, 1479726, 251732291184, 1479726, 120, 1},
%e A157221 {1, 247, 13824739, 16871482830550, 16871482830550, 13824739, 247, 1},
%e A157221 {1, 502, 126781020, 1103881308184906, 113909683214485984529600, 1103881308184906, 
               126781020, 502, 1},
%e A157221 {1, 1013, 1151775897, 71394276041525549, 72042092984864479320451545, 
               72042092984864479320451545, 71394276041525549, 1151775897, 1013, 
               1},
%e A157221 {1, 2036, 10414216090, 4591921534898186048, 45271666954175790151474783510, 
               4826601749447568082372420280481198669200, 45271666954175790151474783510, 
               4591921534898186048, 10414216090, 2036, 1}
%t A157221 Clear[t, n, k];
%t A157221 t[n_, k_] := Sum[(-1)^j Binomial[n + 1, j](k + 1 - j)^n, {j, 0, k + 1}];
%t A157221 f[n_, k_] := If[k <= Floor[n/2], k, n - k];
%t A157221 Table[Table[t[n*f[n, k] + 1, f[n, k]], {k, 0, n}], {n, 0, 10}];
%t A157221 Flatten[%]
%Y A157221 Sequence in context: A154983 A156534 A008292 this_sequence A146967 A156049 
               A101919
%Y A157221 Adjacent sequences: A157218 A157219 A157220 this_sequence A157222 A157223 
               A157224
%K A157221 nonn,tabl,uned
%O A157221 0,5
%A A157221 Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 25 2009