

A277730


Irregular triangle read by rows: T(n,k) = number of times a gap of 2k occurs between the first n successive odd primes.


2



1, 2, 2, 1, 3, 1, 3, 2, 4, 2, 4, 3, 4, 3, 1, 5, 3, 1, 5, 3, 2, 5, 4, 2, 6, 4, 2, 6, 5, 2, 6, 5, 3, 6, 5, 4, 7, 5, 4, 7, 5, 5, 7, 6, 5, 8, 6, 5, 8, 6, 6, 8, 7, 6, 8, 7, 7, 8, 7, 7, 1, 8, 8, 7, 1, 9, 8, 7, 1, 9, 9, 7, 1, 10, 9, 7, 1, 10, 10, 7, 1, 10, 10, 7, 1, 0, 0, 1, 10, 11, 7, 1, 0, 0, 1
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OFFSET

2,2


LINKS

Lars Blomberg, Table of n, a(n) for n = 2..9997 (the first 703 rows)


EXAMPLE

Triangle begins:
1,
2,
2, 1,
3, 1, < gaps in 3,5,7,11,13 are 2 (3 times), 4 (once)
3, 2,
4, 2,
4, 3,
4, 3, 1,
5, 3, 1,
5, 3, 2,
5, 4, 2,
6, 4, 2,
6, 5, 2,
6, 5, 3,
6, 5, 4,
7, 5, 4,
7, 5, 5,
7, 6, 5,
8, 6, 5,
...


CROSSREFS

Cf. A277729, A213930.
Sequence in context: A340985 A259176 A237591 * A174167 A159876 A173493
Adjacent sequences: A277727 A277728 A277729 * A277731 A277732 A277733


KEYWORD

nonn,look,tabf


AUTHOR

N. J. A. Sloane, Nov 06 2016


STATUS

approved



