cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A372753 Integers m, with k digits, such that m = Sum_{i=1..k} A066417(m without its i-th digit).

Original entry on oeis.org

1528, 2970, 19486, 26062, 27670, 37898, 144186, 290814, 331884, 442598, 1010400, 2758596, 4046432, 4270842, 5518368, 5805182, 6826434, 7231218
Offset: 1

Views

Author

Paolo P. Lava, Jul 28 2024

Keywords

Crossrefs

Cf. A066417, A374308, A374309, 374368.

Programs

  • Maple
    with(numtheory): P:=proc(q) local a,b,d,i,j,k,n,t;
    for n from 1 to q do t:=0; a:=convert(n,base,10);
    for b from 1 to nops(a) do d:=0;
    for i from 1 to nops(a) do if i<>b then d:=d*10+a[-i]; fi; od; k:=0; j:=d;
    if d>0 then while j mod 2<>1 do k:=k+1; j:=j/2; od;
    t:=sigma(2*d+1)+sigma(2*d-1)+sigma(d/2^k)*2^(k+1)-6*d-2+t; fi; od;
    if n=t then print(n); fi; od; end: P(10^8);

A374309 Integers m, with k digits, such that m = Sum_{i=1..k} A001065(m without its i-th digit).

Original entry on oeis.org

17940, 159504, 1180140, 2607408, 3478008, 58039388, 111975864, 169084882, 382009288, 942525448, 2014102784, 4978124388, 7360873684
Offset: 1

Views

Author

Paolo P. Lava, Jul 03 2024

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory): P:=proc(q) local a,d,k,i,n,t;
    for n from 1 to q do t:=0; a:=convert(n,base,10);
    for k from 1 to nops(a) do d:=0; for i from 1 to nops(a) do
    if i<> k then d:=d*10+a[-i]; fi; od; t:=sigma(d)-d+t; od;
    if n=t then print(n); fi; od; end: P(10^7)

Extensions

a(6)-a(13) by Giovanni Resta, Jul 06 2024

A374368 Integers m, with k digits, such that m = Sum_{i=1..k} A003415(m without its i-th digit).

Original entry on oeis.org

42080, 150922, 301280, 945688, 1014004, 4962140
Offset: 1

Views

Author

Paolo P. Lava, Jul 06 2024

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory): P:=proc(q) local a,d,i,k,n,p,t;
    for n from 1 to q do t:=0; a:=convert(n,base,10); for k from 1 to nops(a) do
    d:=0; for i from 1 to nops(a) do if i<> k then d:=d*10+a[-i]; fi; od;
    t:=d*add(op(2, p)/op(1, p),p=ifactors(d)[2])+t; od;
    if n=t then print(n); fi; od; end: P(10^7);
Showing 1-3 of 3 results.