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A207890 a(0)=1; for n>=1,- the minimal increasing sequence, such that, for n>=1, the row sums of Pascal-like triangle with left side {1,1,1,...} and right side {a(0), a(1), a(2),...} form an increasing sequence of primes. 2

%I #15 May 01 2014 02:44:24

%S 1,1,2,3,4,5,8,11,14,17,20,29,44,55,66,69,72,77,86,149,152,167,172,

%T 183,198,229,230,233,254,267,276,285,316,355,370,377,402,423,458,469,

%U 478,517,570,623,704,725,730,753,762,801,818,839,858,861,938,943,982

%N a(0)=1; for n>=1,- the minimal increasing sequence, such that, for n>=1, the row sums of Pascal-like triangle with left side {1,1,1,...} and right side {a(0), a(1), a(2),...} form an increasing sequence of primes.

%e Triangle begins

%e n/k.|..0.....1.....2.....3.....4.....5.....6.....7

%e ==================================================

%e .0..|..1

%e .1..|..1.....1

%e .2..|..1.....2.....2

%e .3..|..1.....3.....4.....3

%e .4..|..1.....4.....7.....7.....4

%e .5..|..1.....5....11....14....11.....5

%e .6..|..1.....6....16....25....25....16.....8

%e .7..|..1.....7....22....41....50....41....24.....11

%e .8..|

%e The row sums for n >= 1 form sequence A055496.

%t rows={{1},{1,1}}; Table[(x=Flatten[{1,2 MovingAverage[rows[[n]],2]}]; sx=Apply[Plus,x]; z=NextPrime[sx,NestWhile[#+1&,1,NextPrime[sx,#]-sx<Last[rows[[n]]]&]]-sx; rows=Append[rows,Append[x,z]]),{n,2,100}]; A207890=Map[Last[#]&,rows]

%Y Cf. A055496.

%K nonn,tabl

%O 0,3

%A _Vladimir Shevelev_ and _Peter J. C. Moses_, Feb 21 2012

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)