A015644 - OEIS

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A015644

Number of 5-tuples of different integers from [ 1,n ] with no common factors among quadruples.

0, 0, 0, 0, 1, 6, 21, 52, 121, 226, 431, 688, 1167, 1726, 2651, 3696, 5441, 7140, 10059, 12941, 17287, 21710, 28659, 34724, 44705, 53942, 67131, 79828, 99171, 114846, 140665, 163317, 194706, 224008, 266997, 301436, 356761, 403846

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OFFSET

1,6

LINKS

Table of n, a(n) for n=1..38.

CROSSREFS

Sequence in context: A276072 A135454 A069778 * A067680 A115052 A025203

Adjacent sequences: A015641 A015642 A015643 * A015645 A015646 A015647

KEYWORD

nonn

AUTHOR

Olivier Gérard

STATUS

approved