A329525 a(n) is the smallest positive number k such that k and k+n are both abundant.

5775, 18, 942, 20, 940, 12, 945, 12, 936, 20, 4725, 12, 4712, 40, 930, 20, 928, 12, 2816, 20, 924, 18, 945, 12, 920, 30, 918, 12, 2176, 12, 3465, 24, 912, 20, 910, 12, 7208, 18, 906, 20, 4095, 12, 5312, 12, 900, 20, 945, 12, 896, 20, 894, 18, 4672, 12, 945, 24

Offset

1,1

Comments

Sequences of numbers k such that k and k+n are both abundant for any n: A096399 (n = 1), A231086 (n = 2).

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Example

Number 5775 is the smallest abundant number k such that k+1 = 5576 is also abundant.

Prog

(Magma) [Min([m: m in[1..10^4] | SumOfDivisors(m) gt 2*m and SumOfDivisors(m+n) gt 2*(m+n)]): n in [1..60]];
(PARI) A329525(n) = for(k=1, oo, if((sigma(k) > (k+k)) && (sigma(n+k) > 2*(n+k)), return(k))); \\ Antti Karttunen, Nov 15 2019

Crossrefs

Cf. A005101, A096399, A231086, A294937.

Sequence in context: A235393 A246421 A317049 * A331202 A096399 A071132

Adjacent sequences: A329522 A329523 A329524 * A329526 A329527 A329528

Keyword

nonn

Author

Jaroslav Krizek, Nov 15 2019

Status

approved