[seqfan] PUZZLE of title of A036689
Artur
grafix at csl.pl
Sat Feb 26 23:44:18 CET 2011
Dear Seqfans,
I don't know that titles of sequences was changed by mistake in change
format on WIKI or was wrong at the begining
A036689 Title: Product of a prime and previous number.
Sequence:
Table[Prime[n] (n - 1), {n, 1, 20}]
{0, 3, 10, 21, 44, 65, 102, 133, 184, 261, 310, 407, 492, 559, 658, \
795, 944, 1037, 1206, 1349}
that is A117495
but title is Product of a prime number p and the number of primes
smaller than p.
of course PrimePi[Prime[n]]=n
but easier will be to say: Product of a prime and previous number.
(recent title of A036689)
Best wishes
Artur
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