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A270651 Triangular array:  T(n,k) = greatest m such that 2^m divides prime(n)^2 - prime(k)^2, where 3 <= k <= n. 2
4, 3, 3, 4, 5, 3, 5, 4, 3, 4, 3, 3, 4, 3, 3, 5, 4, 3, 4, 6, 3, 3, 3, 5, 3, 3, 4, 3, 6, 4, 3, 4, 5, 3, 5, 3, 3, 3, 4, 3, 3, 5, 3, 4, 3, 4, 6, 3, 5, 4, 3, 4, 3, 4, 3, 3, 3, 5, 3, 3, 4, 3, 7, 3, 4, 3, 4, 5, 3, 6, 4, 3, 4, 3, 4, 3, 5, 3, 3, 3, 4, 3, 3, 7, 3, 4, 3, 5, 3, 4, 3, 4, 5, 3, 7, 4, 3, 4, 3, 4, 3, 5, 3, 6, 3 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

Clark Kimberling, Table of n, a(n) for n = 3..10000

EXAMPLE

First 9 rows (n = 3 up to 11)::

4

3   3

4   5   3

5   4   3   4

3   3   4   3   3

5   4   3   4   6   3

3   3   5   3   3   4   3

6   4   3   4   5   3   5   3

3   3   4   3   3   5   3   4   3

For n = 5, the numbers p^2 - q^2 are 121 - 9 = 16*7, 121 - 25 = 32*3, 121 - 49 = 8*7, so that row 3 (for n = 5) is (4, 5, 3).

MATHEMATICA

a[n_] := Table[IntegerExponent[Prime[n]^2 - Prime[m]^2, 2], {m, 2, n - 1}]

TableForm[Table[a[n], {n, 2, 16}]]

Flatten[Table[a[n], {n, 2, 16}]]

CROSSREFS

Cf. A000040, A270649.

Sequence in context: A303701 A179845 A180217 * A222635 A222649 A222616

Adjacent sequences:  A270648 A270649 A270650 * A270652 A270653 A270654

KEYWORD

nonn,tabl,easy

AUTHOR

Clark Kimberling, Apr 26 2016

STATUS

approved

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)