A074850 Partial products of successive digits in the decimal expansion of Pi.

3, 3, 12, 12, 60, 540, 1080, 6480, 32400, 97200, 486000, 3888000, 34992000, 244944000, 2204496000, 6613488000, 13226976000, 39680928000, 317447424000, 1269789696000, 7618738176000, 15237476352000, 91424858112000

Offset: 1

Author

Zak Seidov, Sep 10 2002

Keywords

• nonn
• base

Comments

Because 33rd digit in the decimal expansion of Pi, pi(33) = 0, all a(n>32) = 0.

Partial sums of digits of the decimal expansion of Pi are in A046974.

Examples

			a(3)=12 because pi(1)=3, pi(1)=1, pi(3)=4 and a(3)=3*1*4=12.
		

Crossrefs

Cf. A000796, A046974, A073055.

Programs

Mathematica

ppi={3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8, 9, 7, 9, 3, 2, 3, 8, 4, 6, 2, 6, 4, 3, 3, 8, 3, 2, 7, 9, 5, 0, 2, 8}; Table[Product[ppi[[i]], {i, n}], {n, 1, 33}]
Rest[FoldList[Times,1,RealDigits[Pi,10,30][[1]]]] (* Harvey P. Dale, Jan 23 2015 *)

Formula

a(n) = pi(1)*...*pi(n); pi(n)=A000796(n).

a(n) = A073055(n), n>0. - R. J. Mathar, Dec 15 2020